Question

which expression is a factor of $5x^2 - 30x - 80$?
3 pts
a $x + 4$
b $x + 8$
c $x - 4$
d $x - 8$

Explanation:

Step1: Factor out the GCF

Factor 5 from the polynomial:
$5(x^2 - 6x - 16)$

Step2: Factor the quadratic

Find two numbers that multiply to $-16$ and add to $-6$ (these numbers are $-8$ and $2$):
$5(x - 8)(x + 2)$

Step3: Match with options

Compare the factors to the given choices.

Answer:

D. $x - 8$