Question

Which expression is equivalent to 64x^3-343

Answer 1

Answer:

B:  (4x - 7)(16x^2 + 28x + 49)

Step-by-step explanation:

64x^3-343 can be rewritten as 4^3x^3 - 7^3 or (4x)^3 - 7^3.  This is the difference of two cubes.  The appropriate formula for factoring such is

       a^3 - b^3 = (a - b)(a^2 + ab + b^2).  Therefore,

our (4x)^3 - 7^3 = (4x - 7)(16x^2 + 28x + 49).  This is Answer B.