Solve the equation: 4x+(6-x)=18.
解方程：4x+(6-x)=18．
<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<result>4</result>