5n+3+4n=30
First you combine like terms... So...5n+4n=9n
So now you have
9n+3=30
No you subtract 3 from both sides
And 3-3 cancels out and 30-3 is 27 so now you have
9n=27 now you divide 9 on both sides
9/9 cancels out and 27/9 equals 3
So your final answer is....
N=3
