Add 1.5 to 2 times a number, and the sum is 4.3. Find this number. (solution by equation)
一个数的2倍加上1.5，和是4.3，求这个数．(用方程解)
<gadget id="calculator">4.3 - 1.5</gadget>
<output>2.8</output>

<gadget id="calculator">2.8 / 2</gadget>
<output>1.4</output>

<result>1.4</result>