Solve the equation: 6/0.3-4x=12.4.
解方程：6/0.3-4x=12.4．
<gadget id="calculator">6 / 0.3</gadget>
<output>20</output>

<gadget id="calculator">20 - 12.4</gadget>
<output>7.6</output>

<gadget id="calculator">7.6 / 4</gadget>
<output>1.9</output>

<result>1.9</result>