Answer:
5 (x-2) (x²+2x+4)
Step-by-step explanation:
Stating with 5x³ - 40, the want to simplify the x part by extracting the common factor, so
5x³ - 40 = 5(x³-8)
Now to factor x³-8, we can rewrite it in the format x³-2³, right?
And there's a formula to obtain x³-y³, which is the Difference of Cubes formula that goes like this: x³-y³= (x-y)(x²+xy+y²)
So, we apply this formula replacing the y with our value of 2:
x³-2³= (x-2)(x²+2x+2²) = (x-2)(x²+2x+4)
So, overall, we have 5x³ - 40 = 5 (x-2) (x²+2x+4)