-9c+6+4c=21

Solution for -9c+6+4c=21 equation:

Simplifying
-9c + 6 + 4c = 21

Reorder the terms:
6 + -9c + 4c = 21

Combine like terms: -9c + 4c = -5c
6 + -5c = 21

Solving
6 + -5c = 21

Solving for variable 'c'.

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

Add '-6' to each side of the equation.
6 + -6 + -5c = 21 + -6

Combine like terms: 6 + -6 = 0
0 + -5c = 21 + -6
-5c = 21 + -6

Combine like terms: 21 + -6 = 15
-5c = 15

Divide each side by '-5'.
c = -3

Simplifying
c = -3