You start off by multiplying the second bracket by -1 to get rid of the bracket.
So,
(2x3 + x2 - 4x) - 9x3 + 3x2 =
2x3 +x2 - 4x - 9x3 + 3x2 =
(2x3 - 9x3) + (x2 + 3x2) - 4x =
-7x3 + 4x2 - 4x
1-3-1 wdfivijrenveiknefvefvvgr rg
<span>f '(x) = 2(3x2<span> + 5) + 6x(2x - 1)</span></span><span>= 6x2<span> + 10 + 12x</span>2<span> - 6x</span></span><span>= 18x2<span> - 6x + 10</span></span>