8.5*1.2-5.3x=8.5-4x.
8.5*1.2-5.3x=8.5-4x．
<gadget id="calculator">8.5 * 1.2</gadget>
<output>10.2</output>

<gadget id="calculator">10.2 - 8.5</gadget>
<output>1.7</output>

<gadget id="calculator">5.3 - 4</gadget>
<output>1.3</output>

<gadget id="calculator">1.7 / 1.3</gadget>
<output>1.307692</output>

<result>1.307692</result>