Question

como resolve {2x+y=10
2x-y=2

Answer 1

{2x+y=10
{2x-y=2

met. subs.

{x=5-y/2
{2x-y=2

2(5-y/2)-y=2
y=4

subs. a segunda
2x-4=2
2x=2+4
2x=6
x=6/2
x=3                  S={3,4}