Question

Brooke solved the equation below:

6r = 72
6r − 6 = 72 − 6
r = 66

Is Brooke’s solution correct? If the solution is incorrect, explain why it is incorrect and show the correct steps to solve the equation.

Answer 1

Brook:

6r = 72

6r - 6 = 72 - 6

r = 66

Me:

6r = 72

6 x 6 = 36 x 2= 72 so, 6 x 12 = 72

r = 12

Or

6r / 6 = 72 / 6

Both equations have the same result..

r = 12

Explanation:

Brook is incorrect. The reason for this is that when she needed to multiply and divide, she decided to subtract. This ruined her solution because when you're doing the equation in the correct way it'd be 6 x 66 = 396 x 2= 792, where hast the 72 gone?! I've correctly formatted the solution above to show how the problem should have been solved.

Answer 2

No, if 6r = 72, then you would just have to solve for r and divide 72 by 6. r = 12.

6r = 72
72/6 = 12
6(12) = 72