Question

Solve :3x + 4y = 25, 5x - 6y = -9 by elimination method.

Answer 1

$3x+4y=25$ $...\left(1\right)$

$5x-6y=-9$ $...\left(2\right)$

Multiply (1) by 3 and (2) by 2

$9x+12y=75$

$(+)$ $10x-12y$ $=-18$

$19x=57$

$x=3$

Put x = 3 in (2)

$5x-6y=-9$

$5\left(3\right)-6y=-9$

$6y=15+9$

$6y=24$

$y=4$