Answer:
If it's all one multiplication problem:
50x^4 + 100x^3 − 1350x^2 + 5400
Just 50x to the 4th power
plus 100x to the 3rd power
plus 1350x to the 2nd power
plus 5400
If it's two separate problems:
10x^2 - 10x - 60
5x^2 + 15x - 90
5.1m questions
6.7m answers