If you would like to simplify (5 * p^2 - 3) + (2 * p^2 - 3 * p^3), you can calculate this using the following steps:
(5 * p^2 - 3) + (2 * p^2 - 3 * p^3) = 5 * p^2 - 3 + 2 * p^2 - 3 * p^3 = - 3 * p^3 + 7 * p^2 - 3
The correct result would be - 3 * p^3 + 7 * p^2 - 3.