k - 5k^4 - (3k^2 - 5k + 7k^4)...first thing we need to do is to get rid of the parenthesis. So we distribute the negative (or -1) through the parenthesis.
k - 5k^4 - 3k^2 + 5k - 7k^4.....now, u basically just combine like terms...u can rearrange the numbers if it makes it easier...
-5k^4 - 7k^4 - 3k^2 + 5k + k =
-12k^4 - 3k^2 + 6k <===
