Answer:
n=3
Step-by-step explanation:
First, combine like terms on both sides of the equation.
4n+3n-9=2n-5n+21
7n-9=-3n+21
Add 3n to both sides of the equation.
7n-9=-3n+21
10n-9=21
Add 9 to both sides of the equation.
10n-9=21
10n=30
Divide both sides by 10.
10n=30
n=3
