If x=2 is the solution of the equation 3x+4a=22, then a=how much.
如果x=2是方程3x+4a=22的解，则a=多少．
<gadget id="calculator">22 - 6</gadget>
<output>16</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<result>4</result>