Question

x-y+z x+y+2=4 2x+2y-z=-4

Answer 1

x - y + z

x + y + 2 = 4

x + y = 2

2(x + y) = 2•2

2x + 2y = 4

2x + 2y - z = -4

4 - z = -4

z = 8

x + y = 2

y = 2 - x

x - y + z =

x - (2 - x) + 8 =

2x + 6 =

2(x + 3)

Rta:

x - y + z = 2(x + 3)