If you would like to solve -4x^2 * (6x - 5x^2 - 5), you can do this using the following steps:
-4x^2 * (6x - 5x^2 - 5) = -4x^2 * 6x + 4x^2 * 5x^2 + 4x^2 * 5 = -24x^3 + 20x^4 + 20x^2 = 20x^4 - 24x^3 + 20x^2
The correct result would be 20x^4 - 24x^3 + 20x^2.
