A number (3/5) is 7 more than its (1/2), find this number. (Solution of column equation)
一个数(3/5)比它的(1/2)多7，求这个数．(列方程解)
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">7 / (1/10)</gadget>
<output>70</output>

<result>70</result>