The school needs to add 50 sets of desks and chairs. Each desk is 129 yuan, and each chair is 21 yuan. How much will it cost in total?
学校要添制50套课桌椅，桌子每张129元，椅子每张21元，一共要花多少钱？
<gadget id="calculator">129 + 21</gadget>
<output>150</output>

<gadget id="calculator">50 * 150</gadget>
<output>7_500</output>

<result>7_500</result>