Answer:
5. x = 9
6. x = 12
7. x = 15
8. x = 11
Step-by-step explanation:
5. 90-56 = 34
34 = 3x + 7
27 = 3x
x = 9
6. 90 - 48 = 42
42 = 3x + 6
36 = 3x
x = 12
7. 90 - 47 = 43
43 = 2x + 13
30 = 2x
x= 15
8. 3x + 5x + 2 = 90
8x = 88
x = 11