Solve the equation: 7x+4*3.5=24.5.
解方程：7x+4*3.5=24.5．
<gadget id="calculator">4 * 3.5</gadget>
<output>14</output>

<gadget id="calculator">24.5 - 14</gadget>
<output>10.5</output>

<gadget id="calculator">10.5 / 7</gadget>
<output>1.5</output>

<result>1.5</result>