The chemical plant used 864 tons of water in June, saving 74 tons of water compared to May. How many tons of water was used in May? (First list the equation containing the unknown x, and then calculate)
化工厂六月份用水864吨，比五月份节约用水74吨，五月份用水多少吨？(先列出含有未知数x的等式，再计算)
<gadget id="calculator">864 + 74</gadget>
<output>938</output>

<result>938</result>