A product is 39 yuan cheaper after a 30% discount. What is the original price?
一种商品打七折后是便宜39元，原价是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">39 / (3/10)</gadget>
<output>130</output>

<result>130</result>