Trying to simplify $frac{sqrt{8}}{1-sqrt{3x}}$ to be $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$
I am asked to simplify $frac{sqrt{8}}{1-sqrt{3x}}$. The solution is provided as $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$ and I am unable to arrive at this. I was able to arrive at $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Here is my working:
$frac{sqrt{8}}{1-sqrt{3x}}$ = $frac{sqrt{8}}{1-sqrt{3x}}$ * $frac{1+sqrt{3x}}{1+sqrt{3x}}$ = $frac{1+sqrt{8}sqrt{3x}}{1-3x}$ = $frac{1+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x}$ = $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Is $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$ correct and part of the way? How can I arrive at the provided solution $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$?
algebra-precalculus
add a comment |
I am asked to simplify $frac{sqrt{8}}{1-sqrt{3x}}$. The solution is provided as $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$ and I am unable to arrive at this. I was able to arrive at $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Here is my working:
$frac{sqrt{8}}{1-sqrt{3x}}$ = $frac{sqrt{8}}{1-sqrt{3x}}$ * $frac{1+sqrt{3x}}{1+sqrt{3x}}$ = $frac{1+sqrt{8}sqrt{3x}}{1-3x}$ = $frac{1+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x}$ = $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Is $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$ correct and part of the way? How can I arrive at the provided solution $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$?
algebra-precalculus
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago
add a comment |
I am asked to simplify $frac{sqrt{8}}{1-sqrt{3x}}$. The solution is provided as $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$ and I am unable to arrive at this. I was able to arrive at $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Here is my working:
$frac{sqrt{8}}{1-sqrt{3x}}$ = $frac{sqrt{8}}{1-sqrt{3x}}$ * $frac{1+sqrt{3x}}{1+sqrt{3x}}$ = $frac{1+sqrt{8}sqrt{3x}}{1-3x}$ = $frac{1+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x}$ = $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Is $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$ correct and part of the way? How can I arrive at the provided solution $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$?
algebra-precalculus
I am asked to simplify $frac{sqrt{8}}{1-sqrt{3x}}$. The solution is provided as $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$ and I am unable to arrive at this. I was able to arrive at $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Here is my working:
$frac{sqrt{8}}{1-sqrt{3x}}$ = $frac{sqrt{8}}{1-sqrt{3x}}$ * $frac{1+sqrt{3x}}{1+sqrt{3x}}$ = $frac{1+sqrt{8}sqrt{3x}}{1-3x}$ = $frac{1+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x}$ = $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$
Is $frac{1+2sqrt{2}sqrt{3x}}{1-3x}$ correct and part of the way? How can I arrive at the provided solution $frac{2sqrt{2}+2sqrt{6x}}{1-3x}$?
algebra-precalculus
algebra-precalculus
edited 2 days ago
Doug Fir
asked 2 days ago
Doug FirDoug Fir
2967
2967
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago
add a comment |
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago
add a comment |
7 Answers
7
active
oldest
votes
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = color{blue}{frac{sqrt{8}cdotleft({1+sqrt{3x}}right)}{1-3x}} = frac{sqrt{8}+sqrt{24x}}{1-3x}$$
$$= frac{sqrt{2^3}+sqrt{2^3cdot3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
Notice the step I highlighted in blue, which is where you made an error. You have to multiply $sqrt{8}$ to $left(1+sqrt{3x}right)$ completely. You multiplied it by only $sqrt{3x}$ and added $1$, which wasn’t correct.
add a comment |
Observe that
$$
sqrt{8}times (1+sqrt{3x})=sqrt{8}+sqrt{8}times sqrt{3x}
$$ and
$$
sqrt{8}times sqrt{3}=sqrt{24}=sqrt{4times 6}=2sqrt{6}.
$$
add a comment |
Well, in rationalizing the denominator, we arrive at the intermediate step $frac{sqrt{8}+sqrt{24x}}{1-3x}$ which simplifies to the provided solution.
Your error comes in multiplying by the conjugate of the denominator. $sqrt{8}*(1+sqrt{3x})$ becomes $sqrt{8}+sqrt{24x}$.
add a comment |
Write $$frac{sqrt{8}(1+sqrt{3x})}{(1-sqrt{3x})(1+sqrt{3x})}$$ and this is
$$frac{2sqrt{2}(1+sqrt{3x})}{1-3x}$$
add a comment |
Hints:$sqrt8=sqrt{4×2}=2sqrt{2}.$
$sqrt24=2sqrt6$. (Why?)
$(1+sqrt{3x})×(1-sqrt{3x})=1-3x $.
add a comment |
You just made some mistakes in your arithmetic.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = frac{sqrt{8}+sqrt{8}sqrt{3x}}{1-3x} = frac{sqrt{2}sqrt{2}sqrt{2}+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
add a comment |
The second equality is where you mess up - note that
$$sqrt{8}cdot(1+sqrt{3x})=sqrt{8}+sqrt{8}cdotsqrt{3x}$$
by the distributive property of real numbers
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3062999%2ftrying-to-simplify-frac-sqrt81-sqrt3x-to-be-frac2-sqrt22-sqrt%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
7 Answers
7
active
oldest
votes
7 Answers
7
active
oldest
votes
active
oldest
votes
active
oldest
votes
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = color{blue}{frac{sqrt{8}cdotleft({1+sqrt{3x}}right)}{1-3x}} = frac{sqrt{8}+sqrt{24x}}{1-3x}$$
$$= frac{sqrt{2^3}+sqrt{2^3cdot3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
Notice the step I highlighted in blue, which is where you made an error. You have to multiply $sqrt{8}$ to $left(1+sqrt{3x}right)$ completely. You multiplied it by only $sqrt{3x}$ and added $1$, which wasn’t correct.
add a comment |
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = color{blue}{frac{sqrt{8}cdotleft({1+sqrt{3x}}right)}{1-3x}} = frac{sqrt{8}+sqrt{24x}}{1-3x}$$
$$= frac{sqrt{2^3}+sqrt{2^3cdot3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
Notice the step I highlighted in blue, which is where you made an error. You have to multiply $sqrt{8}$ to $left(1+sqrt{3x}right)$ completely. You multiplied it by only $sqrt{3x}$ and added $1$, which wasn’t correct.
add a comment |
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = color{blue}{frac{sqrt{8}cdotleft({1+sqrt{3x}}right)}{1-3x}} = frac{sqrt{8}+sqrt{24x}}{1-3x}$$
$$= frac{sqrt{2^3}+sqrt{2^3cdot3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
Notice the step I highlighted in blue, which is where you made an error. You have to multiply $sqrt{8}$ to $left(1+sqrt{3x}right)$ completely. You multiplied it by only $sqrt{3x}$ and added $1$, which wasn’t correct.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = color{blue}{frac{sqrt{8}cdotleft({1+sqrt{3x}}right)}{1-3x}} = frac{sqrt{8}+sqrt{24x}}{1-3x}$$
$$= frac{sqrt{2^3}+sqrt{2^3cdot3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
Notice the step I highlighted in blue, which is where you made an error. You have to multiply $sqrt{8}$ to $left(1+sqrt{3x}right)$ completely. You multiplied it by only $sqrt{3x}$ and added $1$, which wasn’t correct.
answered 2 days ago
KM101KM101
5,5611423
5,5611423
add a comment |
add a comment |
Observe that
$$
sqrt{8}times (1+sqrt{3x})=sqrt{8}+sqrt{8}times sqrt{3x}
$$ and
$$
sqrt{8}times sqrt{3}=sqrt{24}=sqrt{4times 6}=2sqrt{6}.
$$
add a comment |
Observe that
$$
sqrt{8}times (1+sqrt{3x})=sqrt{8}+sqrt{8}times sqrt{3x}
$$ and
$$
sqrt{8}times sqrt{3}=sqrt{24}=sqrt{4times 6}=2sqrt{6}.
$$
add a comment |
Observe that
$$
sqrt{8}times (1+sqrt{3x})=sqrt{8}+sqrt{8}times sqrt{3x}
$$ and
$$
sqrt{8}times sqrt{3}=sqrt{24}=sqrt{4times 6}=2sqrt{6}.
$$
Observe that
$$
sqrt{8}times (1+sqrt{3x})=sqrt{8}+sqrt{8}times sqrt{3x}
$$ and
$$
sqrt{8}times sqrt{3}=sqrt{24}=sqrt{4times 6}=2sqrt{6}.
$$
answered 2 days ago
Olivier OloaOlivier Oloa
108k17176293
108k17176293
add a comment |
add a comment |
Well, in rationalizing the denominator, we arrive at the intermediate step $frac{sqrt{8}+sqrt{24x}}{1-3x}$ which simplifies to the provided solution.
Your error comes in multiplying by the conjugate of the denominator. $sqrt{8}*(1+sqrt{3x})$ becomes $sqrt{8}+sqrt{24x}$.
add a comment |
Well, in rationalizing the denominator, we arrive at the intermediate step $frac{sqrt{8}+sqrt{24x}}{1-3x}$ which simplifies to the provided solution.
Your error comes in multiplying by the conjugate of the denominator. $sqrt{8}*(1+sqrt{3x})$ becomes $sqrt{8}+sqrt{24x}$.
add a comment |
Well, in rationalizing the denominator, we arrive at the intermediate step $frac{sqrt{8}+sqrt{24x}}{1-3x}$ which simplifies to the provided solution.
Your error comes in multiplying by the conjugate of the denominator. $sqrt{8}*(1+sqrt{3x})$ becomes $sqrt{8}+sqrt{24x}$.
Well, in rationalizing the denominator, we arrive at the intermediate step $frac{sqrt{8}+sqrt{24x}}{1-3x}$ which simplifies to the provided solution.
Your error comes in multiplying by the conjugate of the denominator. $sqrt{8}*(1+sqrt{3x})$ becomes $sqrt{8}+sqrt{24x}$.
answered 2 days ago
GnumbertesterGnumbertester
1285
1285
add a comment |
add a comment |
Write $$frac{sqrt{8}(1+sqrt{3x})}{(1-sqrt{3x})(1+sqrt{3x})}$$ and this is
$$frac{2sqrt{2}(1+sqrt{3x})}{1-3x}$$
add a comment |
Write $$frac{sqrt{8}(1+sqrt{3x})}{(1-sqrt{3x})(1+sqrt{3x})}$$ and this is
$$frac{2sqrt{2}(1+sqrt{3x})}{1-3x}$$
add a comment |
Write $$frac{sqrt{8}(1+sqrt{3x})}{(1-sqrt{3x})(1+sqrt{3x})}$$ and this is
$$frac{2sqrt{2}(1+sqrt{3x})}{1-3x}$$
Write $$frac{sqrt{8}(1+sqrt{3x})}{(1-sqrt{3x})(1+sqrt{3x})}$$ and this is
$$frac{2sqrt{2}(1+sqrt{3x})}{1-3x}$$
answered 2 days ago
Dr. Sonnhard GraubnerDr. Sonnhard Graubner
73.5k42865
73.5k42865
add a comment |
add a comment |
Hints:$sqrt8=sqrt{4×2}=2sqrt{2}.$
$sqrt24=2sqrt6$. (Why?)
$(1+sqrt{3x})×(1-sqrt{3x})=1-3x $.
add a comment |
Hints:$sqrt8=sqrt{4×2}=2sqrt{2}.$
$sqrt24=2sqrt6$. (Why?)
$(1+sqrt{3x})×(1-sqrt{3x})=1-3x $.
add a comment |
Hints:$sqrt8=sqrt{4×2}=2sqrt{2}.$
$sqrt24=2sqrt6$. (Why?)
$(1+sqrt{3x})×(1-sqrt{3x})=1-3x $.
Hints:$sqrt8=sqrt{4×2}=2sqrt{2}.$
$sqrt24=2sqrt6$. (Why?)
$(1+sqrt{3x})×(1-sqrt{3x})=1-3x $.
answered 2 days ago
Thomas ShelbyThomas Shelby
1,907217
1,907217
add a comment |
add a comment |
You just made some mistakes in your arithmetic.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = frac{sqrt{8}+sqrt{8}sqrt{3x}}{1-3x} = frac{sqrt{2}sqrt{2}sqrt{2}+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
add a comment |
You just made some mistakes in your arithmetic.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = frac{sqrt{8}+sqrt{8}sqrt{3x}}{1-3x} = frac{sqrt{2}sqrt{2}sqrt{2}+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
add a comment |
You just made some mistakes in your arithmetic.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = frac{sqrt{8}+sqrt{8}sqrt{3x}}{1-3x} = frac{sqrt{2}sqrt{2}sqrt{2}+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
You just made some mistakes in your arithmetic.
$$frac{sqrt{8}}{1-sqrt{3x}} = frac{sqrt{8}}{1-sqrt{3x}} cdot frac{1+sqrt{3x}}{1+sqrt{3x}} = frac{sqrt{8}+sqrt{8}sqrt{3x}}{1-3x} = frac{sqrt{2}sqrt{2}sqrt{2}+sqrt{2}sqrt{2}sqrt{2}sqrt{3x}}{1-3x} = frac{2sqrt{2}+2sqrt{6x}}{1-3x}$$
answered 2 days ago
greeliousgreelious
15510
15510
add a comment |
add a comment |
The second equality is where you mess up - note that
$$sqrt{8}cdot(1+sqrt{3x})=sqrt{8}+sqrt{8}cdotsqrt{3x}$$
by the distributive property of real numbers
add a comment |
The second equality is where you mess up - note that
$$sqrt{8}cdot(1+sqrt{3x})=sqrt{8}+sqrt{8}cdotsqrt{3x}$$
by the distributive property of real numbers
add a comment |
The second equality is where you mess up - note that
$$sqrt{8}cdot(1+sqrt{3x})=sqrt{8}+sqrt{8}cdotsqrt{3x}$$
by the distributive property of real numbers
The second equality is where you mess up - note that
$$sqrt{8}cdot(1+sqrt{3x})=sqrt{8}+sqrt{8}cdotsqrt{3x}$$
by the distributive property of real numbers
edited 2 days ago
KM101
5,5611423
5,5611423
answered 2 days ago
dromastyxdromastyx
2,2901517
2,2901517
add a comment |
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3062999%2ftrying-to-simplify-frac-sqrt81-sqrt3x-to-be-frac2-sqrt22-sqrt%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Please review your computations. There is a least 2 errors.
– mathcounterexamples.net
2 days ago