Question

A) {X=2y
2x+5y=9

B) {x+y=5
x-y=1

Answer 1

a) {x=2y
2x+5y=9
2.2y+5y=9
4y+5y=9
9y=9
y=9/9
y=1
2x+5y=9
2x+5.1=9
2x+5=9
2x=9-5
2x=4
x=4/2
x=2
S={2, 1}
b) {x+y=5
{x-y=1
2x=6
x=6/2
x=3
x+y=5
3+y=5
y=5-3
y=2
S={3, 2}