The product of a number and its reciprocal plus a is 1 (4/5), what is the reciprocal of a
一个数与它的倒数的积加上a得1(4/5)，a的倒数是多少
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / (4/5)</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>