How would I solve this Math Problem?

Question

12k(1/4k^2-2/3)(k^2+1) How would I solve this using the foil method with fractions?

Answer 1

Just like one without fractions:

12k[(1/4)k^3+(1/4)k^2-(2/3)k^2-2/3]
3k^3+3k^2-8k^2-8
3k^3-5k^2-8

Answer 2

okay first you have to distribute the 12k inside the first set of parentheses. you get

(3k^3 - 8k) (k^2 +1)

now just use the foil method

you get

3k^5 + 3k^3 - 8k^3 - 8k

the answer when you combine like terms is:

3k^5 - 5k^3 - 8k