Help please and explain

Solution for -3c-2=7 equation:
Simplifying
-3c + -2 = 7
Reorder the terms:
-2 + -3c = 7
Solving
-2 + -3c = 7
Solving for variable 'c'.
Move all terms containing c to the left, all other terms to the right.
Add '2' to each side of the equation.
-2 + 2 + -3c = 7 + 2
Combine like terms: -2 + 2 = 0
0 + -3c = 7 + 2
-3c = 7 + 2
Combine like terms: 7 + 2 = 9
-3c = 9
Divide each side by '-3'.
c = -3
Simplifying
c = -3