Three-quarters of a number is 20 more than 50% of the number. What is the number? (solution by equation)
一个数的四分之三比这个数的50%多20，这个数是多少？(用方程解)
<gadget id="calculator">0.75 - 0.5</gadget>
<output>0.25</output>

<gadget id="calculator">20 / 0.25</gadget>
<output>80</output>

<result>80</result>