121 *3/4-3/8*40-0.75 (1/8+1/24+1/48+1/80+1/120+1/168)*56
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121 *3/4-3/8*40-0.75 (1/8+1/24+1/48+1/80+1/120+1/168)*56
(7-11/16*3)+(1-11/16*7)+(5-11/16)+(3-11/16*5)
*是乘号 11/16是十一分之十六
(7-11/16*3)+(1-11/16*7)+(5-11/16)+(3-11/16*5)
*是乘号 11/16是十一分之十六
1. 121*3/4-3/4*1/2*40-3/4
=(121-1/2*40-1)*3/4
=(120-20)*3/4
=100*3/4=75
2.(1/8+1/8*1/3+1/8*1/6+1/8*1/10+1/8*1/15+1/8*1/21)*56
=(1+1/3+1/6+1/10+1/15+1/21)*1/8*56
=(1+1/2+1/6+1/21)*7
=(5/3+1/21)*7
=36/21*7
=12
3.(7-11/16*3)+(1-11/16*7)+(5-11/16)+(3-11/16*5)
=7+1+5+3-11/16*3-11/16*7-11/16-11/16*5
=16-(3+7+1+5)*11/16
=16-16*11/16
=5
这几个题主要考察了混合运算的分配法 呵呵
=(121-1/2*40-1)*3/4
=(120-20)*3/4
=100*3/4=75
2.(1/8+1/8*1/3+1/8*1/6+1/8*1/10+1/8*1/15+1/8*1/21)*56
=(1+1/3+1/6+1/10+1/15+1/21)*1/8*56
=(1+1/2+1/6+1/21)*7
=(5/3+1/21)*7
=36/21*7
=12
3.(7-11/16*3)+(1-11/16*7)+(5-11/16)+(3-11/16*5)
=7+1+5+3-11/16*3-11/16*7-11/16-11/16*5
=16-(3+7+1+5)*11/16
=16-16*11/16
=5
这几个题主要考察了混合运算的分配法 呵呵
121 *3/4-3/8*40-0.75 (1/8+1/24+1/48+1/80+1/120+1/168)*56
(8/1+24/1+48/1+80/1+120//1+168/1)*56
(1/8+1/24+1/48+1/80+1/120+1/168)*56
(1/8+1/24+1/48+1/80+1/120+1/168)乘以56
(8/1+24/1+48/1+80/1+120//1+168/1)*42
(1/8+1/24+1/48+1/80+1/120+1/168+1/224)*64=?
(1/8+1/24+1/48+1/80+1/120+1/168+1/224)*64=
(1/8+1/24+1/48+1/80+1/120+1/168+1/224)乘64
(8/1+24/1+48/1+80/1+120/1+168/1+224/1+288/1)*128
(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/228)*128
(1/8+1/24+1/48+1/80+1/120+1/168)简便计算
42x(8/1+24/1+48/1+80/1+120/1+168/1)=?