6=c-15

Solution for 6=c-15 equation:

Simplifying
6 = c + -15

Reorder the terms:
6 = -15 + c

Solving
6 = -15 + c

Solving for variable 'c'.

Move all terms containing c to the left, all other terms to the right.

Add '-1c' to each side of the equation.
6 + -1c = -15 + c + -1c

Combine like terms: c + -1c = 0
6 + -1c = -15 + 0
6 + -1c = -15

Add '-6' to each side of the equation.
6 + -6 + -1c = -15 + -6

Combine like terms: 6 + -6 = 0
0 + -1c = -15 + -6
-1c = -15 + -6

Combine like terms: -15 + -6 = -21
-1c = -21

Divide each side by '-1'.
c = 21

Simplifying
c = 21