What is the factored form of 5x2 + 28x + 15?

(5x + 3) (x + 5)

(5x + 2) (x + 1)

(5x - 5) (x + 4)

(5x + 1) (x - 4)

Answer: (5x + 3) (x + 5)

Use Foil (first, outer, inner, last)

First is 5x multiplied by x which is 5x^2

Outer is 5x multiplied by 5 which is 25x

Inner is 3 multiplied by x which is 3x

Last is 3 multiplied by 5 which is 15

Now we have 5x^2 + 25x + 3x + 15, combine like terms and you get:

5x^2 + 28x + 15