It says to solve and check.
2 things to remember. First, we need to get the "n" alone (without any other numbers attached). Secondly, whatever you do to one side of the equal sign, you must do to the other.
In order for N+3 to become just "N," we must subtract 3. This is because 3 - 3 = 0.
If I subtract 3 from one side of the equal sign, I must subtract it from the other.
N + 3 (-3) = 10 (-3)
N(+0) = 7, which means that N=7.
In order to check, I need to replace "N" with the value of 7 (because above we just found out that N=7). If it is correct, then both sides of the equals sign would be the same amount
N+3 = 10
(7) + 3 = 10 (All I did was replace the N with 7, which is what I found out earlier).
10=10. It's correct! N does equal 7.