The cafeteria shipped 45 bags of rice. After eating some, there were 28 bags left. How many bags were eaten? (List the equations involving the unknown X, and then solve it.)
食堂运来大米45袋，吃了一些后还剩28袋，吃了多少袋？(列出含有未知数X的等式，再解出来．)
<gadget id="calculator">45 - 28</gadget>
<output>17</output>

<result>17</result>