Add 4 times of a number to its 3 times, the sum is 49.7, find this number.
一个数的4倍加上它的3倍，和是49.7，求这个数．
<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">49.7 / 7</gadget>
<output>7.1</output>

<result>7.1</result>