What is the solution of the equation 5.5x-1.3x=12.6.
方程5.5x-1.3x=12.6的解是多少．
<gadget id="calculator">5.5 - 1.3</gadget>
<output>4.2</output>

<gadget id="calculator">12.6 / 4.2</gadget>
<output>3</output>

<result>3</result>