Question

Find the solution of the given equations
$2x+3y=9$ and $3x+4y=5$.

• A. x = 21, y = 7
• B. x = - 21, y = 17
• C. x = 19, y = 14
• D. x = 20, y = 12

Answer 1

The correct option is B x = - 21, y = 17

$2x+3y=9$ ...(1)

$3x+4y=5$ ...(2)

On multiplying equation (1) by 3, we get

$6x+9y=27$ ...(3)

On multiplying equation (2) by 2, we get

$6x+8y=10$ ...(4)

On subtracting equation (4) from (3), we get

$y=17$

On substituting $y=17$ in equation (1), we get

$2x+3\left(17\right)=9$

$\Rightarrow 2x=9-51=-42$

$\Rightarrow x=\frac{-42}{2}=-21$

$\therefore x=-21andy=17$