[tex]\begin{gathered} \text{the extra monthly interest is} \\ \frac{511.20}{36}=14.2 \\ \\ \text{now, \$14.2 corresponds to the 4\% of the montlhy oricinal price!} \\ \text{the original price mr.mango would pay was} \\ \frac{14.2}{0.04}=335 \\ \\ \text{the monthly price of the new washer and dryer before the payment } \\ \text{plan was \$335} \end{gathered}[/tex]
