-21=-4n-3n

Solution for -21=-4n-3n equation:

Simplifying
-21 = -4n + -3n

Combine like terms: -4n + -3n = -7n
-21 = -7n

Solving
-21 = -7n

Solving for variable 'n'.

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

Add '7n' to each side of the equation.
-21 + 7n = -7n + 7n

Combine like terms: -7n + 7n = 0
-21 + 7n = 0

Add '21' to each side of the equation.
-21 + 21 + 7n = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 7n = 0 + 21
7n = 0 + 21

Combine like terms: 0 + 21 = 21
7n = 21

Divide each side by '7'.
n = 3

Simplifying
n = 3