Question

método da substituição
{4x+4y=52
{-2x-5y=-56

Answer 1

{4x+4y=52
{-2x-5y=-56

4x+4y=52
4x=52-4y
x=52-4y/4
x=13-y

-2.(13-y)-5y=-56
-26+2y-5y=-56
-3y=26-56
-3y=30
y=30/-3
y=-10

x=13-10
x=3