Question

Solve the following equations by elimination method:
$x+y=7$ and $2x-3y=9$

Answer 1

Given equations are

$x+y=7$ ....(1)

and $2x-3y=9$ ....(2)

Multiply equation (1) by $3$, we get

$3x+3y=21$ .... (3)

Add equations (2) and (3) to eliminate $y$,

$5x=30$

$\Rightarrow x=6$

Substitute this value in equation (1), we get

$6+y=7$

$\Rightarrow y=1$

Therefore, the solution is $x=6,y=1$.