Answer:
To simplify:
(3x+4y) - (x-y) = 2x + 5y
To factorize:
(5p + 6)(5p -6)
Step-by-step explanation:
We'll solve this equation in order to find the score of the 4th test, which we denote with x.

. Solving it we find that x=63. And it is the final answer for this problem.
Sort of, say you take 99% off of something that is $100. You will end up paying $1. Then if you take another 99% off, you wil pay $0.01. Takig another 99% off will give you $0.001, but money only goes to two decimal points, so its free from a money standpoint, but there is still a cost.