Question

Factor x2 – 8x + 15.

Which pair of numbers has a product of ac and a sum of b?

Answer 1

Answer:

(x - 5)(x - 3)

Step-by-step explanation:

${x}^{2} - 8x + 15 \\ = {x}^{2} - 5x - 3x + 15 \\ = x(x - 5) - 3(x - 5) \\ = (x - 5)(x - 3) \\ \\ ac = ( - 5) (- 3) = 15 \\ a + c = - 5 - 3 = - 8$