Question

metodo da substituiçao

4x - y = 8

x + y = 7

Answer 1

4x-y=8
x-y=7

4x-y=8
-4x+4y=-28
-y+4y=8-28
3y=20
y=20/3
y=6,6

4x-y=8
4x-6,6=8
4x=6,6+8
x=14,6/4
x=3,65