If x=2 is the solution of equation 8-2x=ax, then a=how much.
若x=2是方程8-2x=ax的解，则a=多少．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<result>2</result>