1. 20x + 5x = 75
25x = 75
To find the answer, divide 75 by 25. The answer is 3.
2. 10x - 4x = 28
6x = 28
That's actually 4.6 repeating. Is that the problem we were supposed to do, or did you make a mistake? In any case, do tell me in the comments whether it was correct, or whether that is indeed the problem for #2.
