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