What is the factored form of 5x2 + 28x + 15? (5x + 3) (x + 5) (5x + 2) (x + 1) ?

5x² + 28x + 15

[ax² + bx + c] Multiply the first term and the last term (a and c) together

5 * 15 = 75 Find the factors of 75 that add or subtract to 28 (b)

Factors of 75: 1, 3, 5, 15, 25, 75 [1 * 75, 3 * 25, 5 * 15]

3 and 25 add up to 28

Instead of 28x:

5x² + 28x + 15

You can replace it with:

5x² + 25x + 3x + 15 [25x and 3x add up to 28x]

Now factor the equation separately. Factor 5x out of (5x² + 25x), and factor 3 out of (3x + 15).

5x (x + 5) + 3 (x + 5) Factor out (x + 5)

(x + 5) (5x + 3) The first option is your answer