Answer:
n = -3
Explanation:
The question is asking you to solve for your variable N. To do so, you must use difference operation(s) and their respective principle of equality to isolate the variable.
To get n by itself on one side of the variable, the term -7n by -7. What you do to one side of the equal sign, you must also do to the other due to the division principle of equality. Thus, you also divide 21 by -7.
Once you simplify, you are left with -3 = n or n = -3, which is your answer.