To buy a car, the installment purchase price will be increased by 7%, and if the cash purchase can be delivered at 85%. Uncle Zhang did the math, and found that paying by installments would cost 7,920 yuan more than buying in cash. How much is the original price of this car.
买一辆汽车，分期付款购买要加价7%，如果现金购买可按85%交货．张叔叔算了算，发现分期付款比现金购买要多付7920元．这辆车的原价是多少元．
<gadget id="calculator">7 / 100</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">(7/100) - (17/20)</gadget>
<output>-39/50 = around -0.78</output>

<gadget id="calculator">1 + (-39/50)</gadget>
<output>11/50 = around 0.22</output>

<gadget id="calculator">7_920 / (11/50)</gadget>
<output>36_000</output>

<result>36_000</result>