Question

Let \[f(x) = (x-1)(x-3)(x+5) + 72.\] Find the sum of all values of $x$ such that $f(x) = 72$.

Answer 1

Explanation:

f(x) = (x-1)(x-3)(x+5) + 72

if f(x) = 72, then

(x-1)(x-3)(x+5)=0

do

x-1=0, x=1

x-3=0, x=3,

x+5=0, x=-5

Answer:

x = 1, 3, -5