How do I simplify this problem.
(2nr - nr^2)r - (2nr - nr^2) . 2r
just use the good old distributive property:
(2nr - nr^2)r - (2nr - nr^2) . 2r
2nr^2 - nr^3 - (2nr^2 - 2nr^3)
2nr^2 - nr^3 - 2nr^2 + 2nr^3
nr^3
(2nr - nr^2)r - (2nr - nr^2) . 2r
(2nr - nr^2)r - (2nr - nr^2) . 2r
2nr^2 - nr^3 - (2nr^2 - 2nr^3)
2nr^2 - nr^3 - 2nr^2 + 2nr^3
nr^3