Go To Your Study Dashboard

Get Answers to all your Questions

header-bg

If and that then:

Option 1)
$y=2x$

Option 2)
$y=-2x$

Option 3)
$y=x$

Option 4)
$y=-x$

Answers (2)

best_answer

As we learnt in

Solution of a non-homogeneous system of linear equations by matrix method -

If $A$ is a non-singular matrix then the system of equations given by $Ax=b$ has a unique solution given by $x=A^{-1}b$

- wherein

$A= \begin{bmatrix} 1 &2 &x \\ 3 &-1 &2 \end{bmatrix}$

$B = \begin{bmatrix} y\\ x\\ 1 \end{bmatrix}$

$AB= \begin{bmatrix} 6\\ 8 \end{bmatrix}$

$\therefore \begin{bmatrix} 1 & 2 & x\\ 3 & -1 & 2 \end{bmatrix} \begin{bmatrix} y\\ x\\ 1 \end{bmatrix}$ $= \begin{bmatrix} 6\\ 8 \end{bmatrix}$

$= \begin{bmatrix} y+ 2x +x\\ 3y- x+ 2 \end{bmatrix}$ $= \begin{bmatrix} 6\\ 8 \end{bmatrix}$

$\Rightarrow y+3x=6$

$-x+3y=6$

$So, y+3x= -x+3y$

$\Rightarrow 4x = 2y$

$\therefore y=2x$

Option 1)

$y=2x$

Incorrect

Option 2)

$y=-2x$

Incorrect

Option 3)

$y=x$

Correct

Option 4)

$y=-x$

Incorrect

Posted by

Aadil

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2026: At IIT Bombay, CSE remains top choice; closing rank falls by 2 points

anam-khan

JEE Main 2026 Registration LIVE: NTA session 1 application soon at jeemain.nta.nic.in; BTech exam dates

anam-khan

JEE Main 2026 Registration LIVE: NTA session 1 applications open soon at jeemain.nta.nic.in; exam dates out

Latest Question