Question

Ajuda 8) Se y = 2x e z = -2y a expressao x - y + z e igual a :

a) 1
b) X
c) -4x
d) -5x

Answer 1

$x - y + z = x - 2x + ( - 2y) = \\ = x - 2x - 2 \times (2x) = \\ = - x - 4x = - 5x$