问题详情:
一次环保知识竞赛共有25道题,规定答对一道题得4分,答错或不答一道题扣1分.在这次竞赛中,小明被评为优秀(85分或85分以上),小明至少答对了几道题?
【回答】
解:设小明答对了x道题,·············································································· 6分
4x-(25-x) ≥85····························································································· 8分
x≥22····························································································· 9分
所以,小明至少答对了22道题.····································································· 10分
知识点:不等式
题型:解答题