Respuesta :

Answer:

x - y = 3

x = 3 + y

y = x - 3

b) 2x - 2y

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

= 6 + 2y - 2x + 6

= - 2x + 2y + 12

Divide all terms by 2

we have

- x + y + 6

c) y - x

= x - 3 - ( 3 + y)

= x - 3 - 3 - y

= x - y - 6

I hope this helps you.