Question

What is the value of the expression –5x4th power when x = –2?

A.
80

B.
40

C.
–40

D.
–80
What is the value of the expression –5 times-2 to the 4th power?

i have done this problem over and over and my answer has been 80 repeatedly. but when i submitted my test it says its -80.

Answer 1

Keep in mind that x^2 is always positive even if x is negative

example:
x = -5
x^2 = x*x = (-5)*(-5) = +25

Answer 2

through similar logic, x^4 is always positive

example:
x = -3
x^4 = x*x*x*x = (-3)*(-3)*(-3)*(-3) = +81

Answer 3

I'm using the idea

(negative) * (negative) = positive

Answer 4

so if x^4 is always positive, then -5x^4 is always negative because

(negative) * (positive) = negative

Answer 5

does that help @nanchita150 ?

Answer 6

thank you @jim_thompson5910 it is letting me respond now and i figured the medal thing out as well

Answer 7

you're welcome