4x+(7/10)=(7/10).
4x+(7/10)=(7/10)．
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(7/10) - (7/10)</gadget>
<output>0</output>

<gadget id="calculator">0 / 4</gadget>
<output>0</output>

<result>0</result>