Exercise 22 Page 8

To solve the given equation for q, we need to isolate it by dividing both sides of the equation by 4. We want to divide it by 4 because multiplication and division are inverse operations — they cancel each other out. This is allowed by the Division Property of Equality.

We will check our solution by substituting this result back into the original equation and simplifying. If doing so results in an identity, our solution is correct.

Since substituting q=13 resulted in an identity, our solution is correct.