作业帮1.1111*9999+9999*7777= 9999*7778+3333*6666=2.(1+2/1)*(1-2/1)*(13/1)*(1-3/1)*.*(1+99/1)*(1-99/1)= 注:2/1是二份之一,其他一样.3.找规律2,4,6,10,16,()()()1,8,27,64,()()1,2,4,7,11,()()()4.甲数的3/2与乙数的40%相等,甲数占乙数的百
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 01:53:42
1.1111*9999+9999*7777= 9999*7778+3333*6666=2.(1+2/1)*(1-2/1)*(13/1)*(1-3/1)*.*(1+99/1)*(1-99/1)= 注:2/1是二份之一,其他一样.3.找规律2,4,6,10,16,()()()1,8,27,64,()()1,2,4,7,11,()()()4.甲数的3/2与乙数的40%相等,甲数占乙数的百
1.1111*9999+9999*7777= 9999*7778+3333*6666=
2.(1+2/1)*(1-2/1)*(13/1)*(1-3/1)*.*(1+99/1)*(1-99/1)= 注:2/1是二份之一,其他一样.
3.找规律
2,4,6,10,16,()()()
1,8,27,64,()()
1,2,4,7,11,()()()
4.甲数的3/2与乙数的40%相等,甲数占乙数的百分之几?
5.2/1+4/1+8/1+16/1+32/1+64/1+128/1=
去年初,甲的存款是乙的3倍,今年初与去年初相比,甲多了2500,乙多了2000远,这是甲 的存款是乙的2被.今年初,甲存款_____元,乙呢?
1.1111*9999+9999*7777= 9999*7778+3333*6666=2.(1+2/1)*(1-2/1)*(13/1)*(1-3/1)*.*(1+99/1)*(1-99/1)= 注:2/1是二份之一,其他一样.3.找规律2,4,6,10,16,()()()1,8,27,64,()()1,2,4,7,11,()()()4.甲数的3/2与乙数的40%相等,甲数占乙数的百
1.(1)原式=(10000-1)*(1111+7777)
=10000*8888-8888
=88880000-8888
=88871112
（2）原式=9999*7778+3333*3*2222
=9999*7778+9999*2222
=9999*(7778+2222)
=9999*10000
=99990000
2.原式=[1²-(2/1)²]*[1²-(3/1)²]*...*[1²-(99/1)²]
=[(2/2)²-(2/1)²]*[(3/3)²-(3/1)²]*...*[(99/99)²-(99/1)²]
=(2²/2²-1)*(3²/3²-1)*...*(99²/99²-1)
=2²*3²*...*99²/(2+1)(2-1)(3+1)(3-1)...(99+1)(99-1)
=2²*3²*...*99²/3*1*4*2*5*3*6*4*...*97*95*98*96*99*97*100*98
=2²*3²*...*99²/1*2*3²*4²*...*97²*98²*99*100
=2*99/100
=99/50
3.(1)2,4,(2+4),(6+4),(10+6),(16+10)=26,(26+16)=42,(42+26)=68
(2)1³,2³,3³,4³,5³=125,6³=216
(3)1,(1+1),(2+2),(4+3),(7+4),(11+5)=16,(16+6)=22,(22+7)=29
4.设甲数为x,乙数就为40%/[(3/2)x]=3/5x
所以,甲数占乙数的3/5,也就是166.67%
5.原式=128/64+128/32+128/16+128/8+128/4+128/2+128/1
=128/127
供参考：
2/1+4/1
=4/3
=1-4/1,
2/1+4/1+8/1
=8/7
=1-8/1,
2/1+4/1+8/1+16/1
=16/15
=1-16/1,
所以2/1+4/1+8/1+16/1+32/1+64/1+128/1
=1-128/1
=128/127