Question

Factor this trinomial.

x2 – 8x + 15

A. (x – 1)(x – 15)
B. (x – 3)(x + 5)
C. (x – 3)(x – 5)
D. (x – 1)(x + 15)

Answer 1

To factor x^2 -8x + 15, we find two numbers that multiply to get 15 and add to get -8. These two numbers can be -5 and -3. Therefore, this factors as

x^2 - 8x + 15 = (x-5)(x-3)

Answer 2

x^2- 8 x+15=0
x^2-5x- 3x +15=0
x(x-5) -3 (x-5)
(x-5)(x-3)