Question

resolva o sistema de equacao x-y =6 x+y = -7

Answer 1

x - y = 6
x + y = - 7

x - y = 6
x = 6 + y

x + y = - 7
x = - 7 - y

6 + y = - 7 - y
y + y = - 7 - 6
2y = - 13
y = - 13/2

x = - 7 - (- 13/2)
x = - 14/2 + 13/2
x = - 1/2