Question

Resolva item d) (7x+y=44 e x-y e x-y=-13)

Answer 1

x - y = -13
x = - 13 + y

7x + y = 44
7 × (- 13 + y) + y = 44
- 91 + 7y + y = 44
8y = 44 + 91
8y = 135
y = 135/8

x = - 13 + y
x = - 13 + 135/8
x = (8 × (- 13))/8 + (1 × 135)/8
x = -104/8 + 135/8
x = 31/8