Wang Hua walked the full length (2/5) from point A to point B, 15 kilometers away from the midpoint. What is the formula for finding the total length of places A and B
王华从甲地到乙地，走了全长的(2/5)，离中点还有15千米．求甲乙两地全长的算式是多少
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">15 / (1/10)</gadget>
<output>150</output>

<result>150</result>