Question

1) {4y-x=11
{6y-2x=13
2) {2x +3y=16
{3X-2Y=11

Answer 1

1) {4y-x=11
{6y-2x=13

-x=11-4y
6y-2x=13

x=4y-11
6y-2(4y-11)=13

x=4y-11
6y-8y+22=13

x=4y-11
-2y=13-22

x=4×4.5-11
y=4.5

x=7
y=4.5

2) {2x +3y=16
{3X-2Y=11

2x=16-3y => x=(16-3y)2
3×(16-3y)/2-2y=11 => (48-9y)/2=11+2y => 48-9y=2×(11+2y) => -9y-4y=22-48 =>-13y= -26 => y=2

x=(16-3×2)/2=5