Question

MEDAL FOR THE CORRECT ANSWER!!!

Has the polynomial below been factored correctly and completely? Explain your answer.
x5 - 16x3 + 8x2 - 128
x3(x2 - 16) + 8(x2 - 16)
(x2 -16)(x3 + 8)

Answer 1

yes, you used factoring by grouping
but x^2-16 is a difference of squares
(x-4)(x+4)(x^3+8)

Answer 2

so basically you need to keep factoring if possible
actually we could even factor x^3 + 8 because it is a sum of cubes

Answer 3

thanks so much for your help! :) i really appreciate it :)

Answer 4

i gave you a medal!

Answer 5

http://www.purplemath.com/modules/specfact2.htm