90又9/1*89又9/8=?
问题描述：
90又9/1*89又9/8=?
答
=(90+1/9)+(90-1/9)
=90+90+(1/9-1/9)
=180
90又9/1*89又9/8=?
=(90+1/9)+(90-1/9)
=90+90+(1/9-1/9)
=180