Question

If $[\begin{array}{cc}3x+7& 5\\ y+1& 2-3x\end{array}]=[\begin{array}{cc}1& y-2\\ 8& 8\end{array}]$, then the values of x and y respectively are

• A. $-2,7$
• B. $-\frac{1}{3},7$
• C. $-\frac{1}{3},-\frac{2}{3}$
• D. $2,-7$

Answer 1

The correct option is A $-2,7$

$\left[\begin{array}{cc}3x+7& 5\\ y+1& 2-3x\end{array}\right]=\left[\begin{array}{cc}1& y-2\\ 8& 8\end{array}\right]$

Comparing both sides corresponding columns of both sides.

$\Rightarrow 3x+7=1$ $\&$ $y-2=5$

$\Rightarrow 3x=-6,$ $y=7$

$\Rightarrow x=-2,$ $y=7$

Hence, the answer is $-2,7.$