The school bought 85 sets of desks and chairs, one desk is 69 yuan, and one chair is 31 yuan. How much is the total cost?
学校买来85套课桌椅，一张课桌69元，一把椅子31元，一共要用多少元？
<gadget id="calculator">69 + 31</gadget>
<output>100</output>

<gadget id="calculator">100 * 85</gadget>
<output>8_500</output>

<result>8_500</result>