You have the following equation:
7n + 14 = -21
In order to solve the previous equation, proceed as follow:
7n + 14 = -21 subtract 14 both sides
7n = -21 - 14 simplify right side
7n = -35 divide by 7 both sides
n = -35/7
n = -5
Hence, the solution to the given equation is n = -5
To verufy if the solution is the right answer, it is only necessary to repalce the value of n into the given equation, and to check if the equation is consisten, just as follow:
7n + 14 = -21
7(-5) + 14 = -21
-35 + 14 = -21
-21 = -21
as you can notice, the equation is consistent. Hence, n = -5 is the right answer.