Question

23-26 algebra 1 unit 7 test

1. which expression is a factor of $5x^2 - 30x - 80$?

$x + 4$
$x + 8$
$x - 4$
$x - 8$
clear all

Explanation:

Step1: Factor out GCF

First, factor out the greatest common factor (GCF) of the terms in $5x^2 - 30x - 80$. The GCF of 5, -30, and -80 is 5.
$5(x^2 - 6x - 16)$

Step2: Factor quadratic trinomial

Factor the quadratic $x^2 - 6x - 16$. We need two numbers that multiply to $-16$ and add to $-6$. These numbers are $-8$ and $+2$.
$5(x - 8)(x + 2)$

Step3: Identify matching factor

Compare the factored form to the given options. One of the factors is $x - 8$.

Answer:

D. $x - 8$