Solve the equation: 60%y+4.2=8.7.
解方程：60%y+4.2=8.7．
<gadget id="calculator">8.7 - 4.2</gadget>
<output>4.5</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4.5 / (3/5)</gadget>
<output>7.5</output>

<result>7.5</result>