## Elementary Algebra

At the beginning, Caleb pays 400 dollars. After a roommate leaves, Caleb will pay 536 dollars. To find the percentage change in his rent, we use the following formula: Percent change = $\frac{New\ amount\ -\ Original\ amount}{Original\ amount}$ $\times$ 100% The original amount is 400, and the new one is 536. We substitute these values into the formula to obtain: Percentage change = $\frac{536\ -\ 400}{400}$ $\times$ 100% Percentage change = $\frac{136}{400}$ $\times$ 100% Percentage change = 0.34 $\times$ 100% Percentage change = 34%