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简便计算3.3x3.4+3.4x3.5+3.5x3.6+3.6x3.7简便计算1.3.3x3.4+3.4x3.5+3.5x3.6+3.6x3.72.1/21+1/30+1/42+1/56+1/72+1/903.19/24x85+109x5/24

题目详情
简便计算3.3x3.4+3.4x3.5+3.5x3.6+3.6x3.7
简便计算1 .3.3x3.4+3.4x3.5+3.5x3.6+3.6x3.7 2.1/21+1/30+1/42+1/56+1/72+1/90 3.19/24x85+109x5/24
▼优质解答
答案和解析
1 3.3x3.4+3.4x3.5+3.5x3.6+3.6x3.7= 2. 1/21+1/30+1/42+1/56+1/72+1/90 =1/21+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10 =1/21+1/5-1/10=1/21+1/10=31/210 3.19/24x85+109x5/24 =