Question

Which of the following is a factor of 64x^3 +343

Answer 1

(4x - 7)(16x^2 + 28x + 49)

Answer 2

Answer:

(4x + 7) or

(16x^2 - 28x + 49)

Step-by-step explanation:

This is the sum of cubes. If you have choices you really should list them because often the way  we write  answers is not in agreement with what you are given.

Step One

Factor 64x^3  and 343 into prime factors.

64x^3: 4*4*4*x * x *x

343: 7 * 7 * 7

Step Two

Factor using the sum of cubes.

(4x + 7)([4x]^2 - 7*4x + 7^2)

(4x + 7)(16x^2 - 28x + 49)