Question

Resolva o sistema
x+y=10
2x+2y=20

Answer 1

x=5  y=5, pois 2x=2.x=10 + 2y=2.y=10   e 2x+2y= 10+10

Answer 2

X=10-y
2(10-y)+2y=20
20+2y+2y=20
4y=20-20
y=0


x=10-0
x=10
S={10,0}