Question

Solve $x-y+2=0$
$7x+9y=130$

Answer 1

$x-y+2=0$ ------- (1)

$7x+9y=130$ ------(2)

multiply equation 1 by $7$.

we get ,

$7x-7y+14=0$ ---- (3)

Now subtract (3) from (2).

we get ,

$y=9$

put $y=9$ in (1)

we get ,

$x=7$