(1/2) plus 85% of a number is exactly equal to 0.75. Find this number. (solution by equation)
(1/2)加上一个数的85%，正好等于0.75，求这个数．(用方程解)
<gadget id="calculator">0.75 - 0.5</gadget>
<output>0.25</output>

<gadget id="calculator">0.25 / 0.85</gadget>
<output>0.294118</output>

<result>0.294118</result>