Determining $x_2$ in the solution of the system












0












$begingroup$


Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$
when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$

using Cramer's rule.



Options to choose from:




  1. $-4$

  2. $4$

  3. $6$

  4. $-2$


My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$



I got $x_2=dfrac24$ which is not an option to choose. How do I do?










share|cite|improve this question











$endgroup$












  • $begingroup$
    Do you mean determinant of matrix is $4$?
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:35










  • $begingroup$
    The information that I get from the task is that the 3x3 matrix is equal to 4
    $endgroup$
    – anders
    Dec 20 '18 at 9:37










  • $begingroup$
    The vertical lines are just another notion for the determinant of a matrix.
    $endgroup$
    – Student7
    Dec 20 '18 at 10:22
















0












$begingroup$


Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$
when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$

using Cramer's rule.



Options to choose from:




  1. $-4$

  2. $4$

  3. $6$

  4. $-2$


My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$



I got $x_2=dfrac24$ which is not an option to choose. How do I do?










share|cite|improve this question











$endgroup$












  • $begingroup$
    Do you mean determinant of matrix is $4$?
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:35










  • $begingroup$
    The information that I get from the task is that the 3x3 matrix is equal to 4
    $endgroup$
    – anders
    Dec 20 '18 at 9:37










  • $begingroup$
    The vertical lines are just another notion for the determinant of a matrix.
    $endgroup$
    – Student7
    Dec 20 '18 at 10:22














0












0








0





$begingroup$


Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$
when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$

using Cramer's rule.



Options to choose from:




  1. $-4$

  2. $4$

  3. $6$

  4. $-2$


My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$



I got $x_2=dfrac24$ which is not an option to choose. How do I do?










share|cite|improve this question











$endgroup$




Task:
Determine $x_2$ in the solution of the system$$
begin{bmatrix}4&a&0\6&b&2\9&c&3end{bmatrix}begin{bmatrix}x_1\x_2\x_3end{bmatrix}=begin{bmatrix}1\2\0end{bmatrix}$$
when$$
left|begin{matrix}4&a&0\6&b&2\9&c&3end{matrix}right|=4$$

using Cramer's rule.



Options to choose from:




  1. $-4$

  2. $4$

  3. $6$

  4. $-2$


My answer:
$$begin{bmatrix}x_1\x_2\x_3end{bmatrix}×4=begin{bmatrix}1\2\0end{bmatrix}$$



I got $x_2=dfrac24$ which is not an option to choose. How do I do?







linear-algebra systems-of-equations






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 20 '18 at 10:01









Yadati Kiran

1,7911619




1,7911619










asked Dec 20 '18 at 9:30









andersanders

615




615












  • $begingroup$
    Do you mean determinant of matrix is $4$?
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:35










  • $begingroup$
    The information that I get from the task is that the 3x3 matrix is equal to 4
    $endgroup$
    – anders
    Dec 20 '18 at 9:37










  • $begingroup$
    The vertical lines are just another notion for the determinant of a matrix.
    $endgroup$
    – Student7
    Dec 20 '18 at 10:22


















  • $begingroup$
    Do you mean determinant of matrix is $4$?
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:35










  • $begingroup$
    The information that I get from the task is that the 3x3 matrix is equal to 4
    $endgroup$
    – anders
    Dec 20 '18 at 9:37










  • $begingroup$
    The vertical lines are just another notion for the determinant of a matrix.
    $endgroup$
    – Student7
    Dec 20 '18 at 10:22
















$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35




$begingroup$
Do you mean determinant of matrix is $4$?
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:35












$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37




$begingroup$
The information that I get from the task is that the 3x3 matrix is equal to 4
$endgroup$
– anders
Dec 20 '18 at 9:37












$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22




$begingroup$
The vertical lines are just another notion for the determinant of a matrix.
$endgroup$
– Student7
Dec 20 '18 at 10:22










1 Answer
1






active

oldest

votes


















1












$begingroup$

$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.




$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$







share|cite|improve this answer











$endgroup$













  • $begingroup$
    what is the second column in A?
    $endgroup$
    – anders
    Dec 20 '18 at 9:41










  • $begingroup$
    Its $(a: b: c)^T$
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:41












  • $begingroup$
    what does the delta mean?
    $endgroup$
    – anders
    Dec 20 '18 at 9:43










  • $begingroup$
    Delta means determinant of matrix concerned.
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:44










  • $begingroup$
    sorry for being stupid but I don't understand how I should do
    $endgroup$
    – anders
    Dec 20 '18 at 9:45











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
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3047341%2fdetermining-x-2-in-the-solution-of-the-system%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









1












$begingroup$

$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.




$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$







share|cite|improve this answer











$endgroup$













  • $begingroup$
    what is the second column in A?
    $endgroup$
    – anders
    Dec 20 '18 at 9:41










  • $begingroup$
    Its $(a: b: c)^T$
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:41












  • $begingroup$
    what does the delta mean?
    $endgroup$
    – anders
    Dec 20 '18 at 9:43










  • $begingroup$
    Delta means determinant of matrix concerned.
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:44










  • $begingroup$
    sorry for being stupid but I don't understand how I should do
    $endgroup$
    – anders
    Dec 20 '18 at 9:45
















1












$begingroup$

$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.




$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$







share|cite|improve this answer











$endgroup$













  • $begingroup$
    what is the second column in A?
    $endgroup$
    – anders
    Dec 20 '18 at 9:41










  • $begingroup$
    Its $(a: b: c)^T$
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:41












  • $begingroup$
    what does the delta mean?
    $endgroup$
    – anders
    Dec 20 '18 at 9:43










  • $begingroup$
    Delta means determinant of matrix concerned.
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:44










  • $begingroup$
    sorry for being stupid but I don't understand how I should do
    $endgroup$
    – anders
    Dec 20 '18 at 9:45














1












1








1





$begingroup$

$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.




$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$







share|cite|improve this answer











$endgroup$



$underline{text{Cramer's rule:}}$ $x_i=dfrac{Delta_i}{Delta }$ where $Delta_i$ is the determinant of matrix $A$ with its $i^{th}$ column replaced by vector $b$ and $Delta$ is the determinant of the matrix $A$.




$$x_2=dfrac{left|begin{matrix}4 &1 &0\6 &2 &2\9 &0 &3end{matrix}right|}{4}=dfrac{24}{4}=6$$








share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 20 '18 at 10:08

























answered Dec 20 '18 at 9:38









Yadati KiranYadati Kiran

1,7911619




1,7911619












  • $begingroup$
    what is the second column in A?
    $endgroup$
    – anders
    Dec 20 '18 at 9:41










  • $begingroup$
    Its $(a: b: c)^T$
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:41












  • $begingroup$
    what does the delta mean?
    $endgroup$
    – anders
    Dec 20 '18 at 9:43










  • $begingroup$
    Delta means determinant of matrix concerned.
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:44










  • $begingroup$
    sorry for being stupid but I don't understand how I should do
    $endgroup$
    – anders
    Dec 20 '18 at 9:45


















  • $begingroup$
    what is the second column in A?
    $endgroup$
    – anders
    Dec 20 '18 at 9:41










  • $begingroup$
    Its $(a: b: c)^T$
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:41












  • $begingroup$
    what does the delta mean?
    $endgroup$
    – anders
    Dec 20 '18 at 9:43










  • $begingroup$
    Delta means determinant of matrix concerned.
    $endgroup$
    – Yadati Kiran
    Dec 20 '18 at 9:44










  • $begingroup$
    sorry for being stupid but I don't understand how I should do
    $endgroup$
    – anders
    Dec 20 '18 at 9:45
















$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41




$begingroup$
what is the second column in A?
$endgroup$
– anders
Dec 20 '18 at 9:41












$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41






$begingroup$
Its $(a: b: c)^T$
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:41














$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43




$begingroup$
what does the delta mean?
$endgroup$
– anders
Dec 20 '18 at 9:43












$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44




$begingroup$
Delta means determinant of matrix concerned.
$endgroup$
– Yadati Kiran
Dec 20 '18 at 9:44












$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45




$begingroup$
sorry for being stupid but I don't understand how I should do
$endgroup$
– anders
Dec 20 '18 at 9:45


















draft saved

draft discarded




















































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.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3047341%2fdetermining-x-2-in-the-solution-of-the-system%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

Wiesbaden

Marschland

Dieringhausen