Question

expressions and equations
question 3/14
given x = -2, y = 5, and z = -1, what is the value of the expression 2x² + 4y - 2z³?
select one answer
a -40
b -8
c 8

Explanation:

Step1: Substitute given values

Substitute $x=-2$, $y=2$, $z=-4$ into $2x^3 + 4y - 2z^2$:
$2(-2)^3 + 4(2) - 2(-4)^2$

Step2: Calculate each term

Calculate powers first, then multiplication:
$2(-8) + 8 - 2(16) = -16 + 8 - 32$

Step3: Compute final sum

Add and subtract left to right:
$-16 + 8 = -8$; $-8 - 32 = -40$

Answer:

A. -40