5 times a number plus the product of 1.7 and 3, the sum is 8.6, what is this number?
一个数的5倍加上1.7与3的积，和是8.6，这个数是多少？
<gadget id="calculator">1.7 * 3</gadget>
<output>5.1</output>

<gadget id="calculator">8.6 - 5.1</gadget>
<output>3.5</output>

<gadget id="calculator">3.5 / 5</gadget>
<output>0.7</output>

<result>0.7</result>