The school is going to buy 42 sets of desks and chairs (a desk and a chair are a set of desks and chairs). It is known that each desk is 55 yuan and each chair is 45 yuan. How much is the total cost? (answer in two ways)
学校准备购买42套课桌椅(一张桌子和一把椅子为一套课桌椅)，已知每张桌子55元，每把椅子45元，一共需要多少元？(用两种方法解答)
<gadget id="calculator">55 * 42</gadget>
<output>2_310</output>

<gadget id="calculator">45 * 42</gadget>
<output>1_890</output>

<gadget id="calculator">2_310 + 1_890</gadget>
<output>4_200</output>

<result>4_200</result>