Question

Anna wants to factor the polynomial p(x)=5x^4+40x. She knows that the sum of cubes formula is a^3+b^3=(a+b)(a^2−ab+b^2).

Answer 1

Answer:

Part A:  Option 2, A: Anna’s answer is incorrect. She correctly factored out 5x, but incorrectly identified a and b, so her answer cannot be correct.

Part B:  Option 3, B: 5x(x+2)(x^2−2x+4)

Step-by-step explanation:

p(x) = 5x^4 + 40x

p(x) = 5x(x^3 + 8)

p(x) = 5x(x + 2)(x^2 - 2x + 4)

Part A:  Option 2, A: Anna’s answer is incorrect. She correctly factored out 5x, but incorrectly identified a and b, so her answer cannot be correct.

Part B:  Option 3, B: 5x(x+2)(x^2−2x+4)