Multiply 7.8 by the sum of 11 and 89, and then subtract 609, what is the difference?
7.8乘以11与89的和，再减去609，差是多少？
<gadget id="calculator">11 + 89</gadget>
<output>100</output>

<gadget id="calculator">7.8 * 100</gadget>
<output>780</output>

<gadget id="calculator">780 - 609</gadget>
<output>171</output>

<result>171</result>