Solve the equation: (x-4.5)*1.8=7.2.
解方程：(x-4.5)*1.8=7.2．
<gadget id="calculator">4.5 * 1.8</gadget>
<output>8.1</output>

<gadget id="calculator">8.1 + 7.2</gadget>
<output>15.3</output>

<gadget id="calculator">15.3 / 1.8</gadget>
<output>8.5</output>

<result>8.5</result>