Question

Brooke solved the equation below:

6r = 72
6r − 6 = 72 − 6
r = 66

Is Brooke's solution correct?

Answer 1

Let's solve 6r = 72
6r = 72
/6     /6 <-----Divide by 6 to isolate the 'r'
r = 12 <--------Answer.

Brooke is not correct; the solution is 12. She subtracted 6 from both sides rather than divided it, this is where she errs.