能简算的要简算 1/30+1/42+1/56+1/72
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/07/05 17:27:44
能简算的要简算 1/30+1/42+1/56+1/72
能简算的要简算
1/30+1/42+1/56+1/72
能简算的要简算
1/30+1/42+1/56+1/72
1/(5×6)+1/(6×7)+1/(7×8)+1/(8×9)
=(1×7)/(5×6×7)+(1×5)/(5×6×7)+(1×9)/(7×8×9)+(1×7)/(7×8×9)
=7/(5×6×7)+5/(5×6×7)+9/(7×8×9)+7/(7×8×9)
=(5+7)/(5×6×7)+(7+9)/(7×8×9)
=12/(5×6×7)+16/(7×8×9)
=(2×6)/(5×6×7)+(2×8)/(7×8×9)
=2/(5×7)+2/(7×9)
=(2×9)/(5×7×9)+(2×5)/(5×7×9)
=(2×14)/(5×7×9)
=(2×2×7)/(5×7×9)
=(2×2)/(5×9)
=4/45
=(1×7)/(5×6×7)+(1×5)/(5×6×7)+(1×9)/(7×8×9)+(1×7)/(7×8×9)
=7/(5×6×7)+5/(5×6×7)+9/(7×8×9)+7/(7×8×9)
=(5+7)/(5×6×7)+(7+9)/(7×8×9)
=12/(5×6×7)+16/(7×8×9)
=(2×6)/(5×6×7)+(2×8)/(7×8×9)
=2/(5×7)+2/(7×9)
=(2×9)/(5×7×9)+(2×5)/(5×7×9)
=(2×14)/(5×7×9)
=(2×2×7)/(5×7×9)
=(2×2)/(5×9)
=4/45
能简算的要简算 1/30+1/42+1/56+1/72
简便运算,能简算的要简算9分之4÷[(3分之2-9分之2)×2分之1等于?42分之1+56分之1+72分之1+90分之
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
能简算的要简算.10.2-(1.25+2.5)÷1.5 480÷16×1
递等式计算(能简算的要简算):75×1/4+25×25%
9.6-11÷7+1/7x4 能简算的要简算 速度采纳
42/1+56/1+72/1+90/1+110/1
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=?
30/1+42/1+56/1=?
1的平方+2的平方+3的平方+4的平方+5的平方+6的平方+…+2012的平方+2013的平方+2014的平方
简算:1+12/6+36/12+80/20+150/30+252/42+392/56+576/72
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90简便运算怎么做