i have 5 questions, i don't know how to solve these questions.

7= 2 +5(z-2)

15(s-3)=12s-43

2a-6=3(a-4)

2(b-3)+5=3(b-1)

6x +7 / 5 = x

7= 2 +5(z-2)

First perform the process within parentheses.

7 = 2 + 5z - 10
7 = 5z - 8

Get the knowns on one side and the unknowns on the other side. Add 8 to both sides.

15 = 5z
15/5 = z
3 = z
-----------------------

15(s-3)=12s-43
15s - 45 = 12s - 43
3s = 45 - 43
3s = 2
s = 2/3
------------------------------------

Follow this procedure for the other problems. I'll be glad to check your answers.