To find this answer we must plug in the values given and then rearrange the equation to solve for e (number of erasers). First we can rearrange the equation for e to get the following expression: (P + 5)/.5 = e . Now we just plug in the $63 profit for P and solve for e. Doing this we get: (63 + 5)/.5 = 68/.5 = 136. Jennifer sold 136 erasers.
