Question

Determine X, Y e Z que satisfaçam:
(x+y 2)=(7 z)
( 4 x-y)=(z² 1)

Answer 1

x+y=7
x-y=1
____
2x=8
x=8/2
x=4

x+y=7
4+y=7
y=7-4
y=3

z=2

z²=4
z=±√4
z=±2