Which factors can be multiplied together to make the trinomial 5x2 + 8x – 4? check all that apply.

Which factors can be multiplied together to make the trinomial 5x2 + 8x – 4? Check all that apply.

(x + 1)

(2x + 1)

(x + 2)

(5x + 1)

(5x – 2)

Solution :

By multiplying (5x - 2) and (x + 2), the given trinomial will be obtain as follow. 
 (5x - 2) * (x + 2) = (5x * x) + (5x * 2) - (2 * x) - (2 * 2)
=  5x^2 + 10x - 2x - 4
= 5x^2 + 8x - 4

What the heck don’t understand