3/4+1/20+1/30+1/42+1/56+1/72 求如何简便计算快啊!!!!!!!!!!!!
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3/4+1/20+1/30+1/42+1/56+1/72 求如何简便计算快啊!!!!!!!!!!!!
3/4+1/20+1/30+1/42+1/56+1/72 求如何简便计算
快啊!!!!!!!!!!!!
3/4+1/20+1/30+1/42+1/56+1/72 求如何简便计算快啊!!!!!!!!!!!!
3/4+1/20+1/30+1/42+1/56+1/72
=3/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=1-1/9
=8/9
如果本题有什么不明白可以追问,
3/4+1/20+1/30+1/42+1/56+1/72
=3/4+1/4*5+1/5*6+1/6*7+1/7*8+1/8*9
=3/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=3/4+1/4-1/9
=1-1/9
=8/9
不懂可追问
满意请采纳
谢谢
1/20=1/4-1/5
1/30=1/5-1/6
1/42=1/6-1/7
1/56=1/7-1/8
1/72=1/8-1/9
3/4+1/20+1/30+1/42+1/56+1/72
=3/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=1-1/9
=8/9
1/3-1/12-1/20-1/30-1/42
1-1/4+1/20+1/30+1/42+1/56简便计算哦
3/4+1/20+1/30+1/42+1/56+1/72 求如何简便点的计算
3/4+1/20+1/30+1/42+1/56+1/72 求如何简便计算快啊!!!!!!!!!!!!
已知1/6=1/2-1/3,1/12=1/3-1/4,1/20=1/4-1/5,那么1/6+1/12+1/20+1/30+1/42+1/56=?
(1/3)-(1/6)-(1/12)-(1/20)-(1/30)-(1/42)
1/3+1/15+1/35+1/63+1/99(1+1/2)(1+1/3)(1+1/4)……(1+1/100)1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/901/12+1/20+1/30+1/42
1/6+1/12+1/20+1/30+1/42
1/6+1/12+1/20+1/30+1/42
1/12+1/20+1/30+1/42+.+1/2450
求比值 184:92 20:0.5 42:1.4 3/4:16/9 30/1:6/1
1/2 + 1/6 + 1/12 + 1/20 + 1/30+ 1/42 + 1/56 + 1/72=(1+ 1/2+ 1/3+ 1/4+ 1/5)×(1/2+ 1/3+ 1/4+ 1/5+ 1/6)-(1+ 1/2+ 1/3+ 1/4+1/5+ 1/6)×(1/2+ 1/3+ 1/4+ 1/5)
计算:1 6/1+2 12/1+3 20/1+4 30/1+5 42/1+6 56/1+7 72/1
4,2,1,1/2,1/4,( ) ( ) ( )1/8,1/32,1/4 ,1/16( )( ) ( )1/2,1/6,1/12,1/20,1/30,1/42 ( ) ( ) ( )
1*2=1/2+1/6,1/2*3=1/6+1/12+1/20,1/4*4=1/20=1/30+1/42+1/56,求2/1*2014=?“ * ”指的是特殊符号
1+2又1/8+3又1/12+4又1/20+5又1/30-6又1/42+7又1/56+8又1/42+9又1/42
1/20+1/30+1/42+1/56简便计算,
1/20+1/30+1/42+……+1/132