20x^4-39x^3-16x
Make sure to multiply all the terms by each other in the two parentheses
12(2a-b) would be your answer :)
(3a-7)^2
1. 9a^2-21a-21a+49
2. 3a(3a-7)-7(3a-7)
3. (3a-7)(3a-7)
4. Combine like terms
4. division by zero is not allowed because zero has nothing to divide
