Question

Factor Completely: 2x2 - 200 A) (x - 20)(x +10) B) (x - 10)(x + 10) C) 2(x - 4)(x + 50) D) 2(x + 10)(x - 10)

Answer 1

D) 2(x + 10)(x - 10)

Explanation:

2x^2 - 200

factor out a 2

2(x^2 -100)

both x^2 and 100 are squares so

a^2 – b^2 = (a + b)(a – b)

a=x and b = 10

2(x^2 -100) = 2( x-10 )(x+10)

= 2(x+10) (x-10) the order in which we multiply doesn't matter