1+1+1+1+1+1+1+1+1+1+1+1+11++1+1+1+11+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1-2+2+2+2+2+2+2-12221+21
a.1/6+1/12+1/20+1/30+1/42+............+1/90+1/110
b.2/11*13+2/13*15+2/15*17+..........+2/97*99+2/99*101
c.1/11*16+1/16*21+1/21*26+.................+1/56*61+1/61*66
1+0+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+11+1+1++1+11+1+1+1+1+1+1+1+2+2+2+2+2+2222+33333+444+555+666+777+888+999-{1+0+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+11+1+1++1+11+1+1+1+1+1+1+1+2+2+2+2+2+2222+33333+444+555+666+777+888+999-}
lớp 1 học cái này à:(((??
Tính
A=13/21.2/11+13/21.9/11+8/21.
B=(1-1/5).(1-2/5).(1-3/5)...(1-9/5)
C= (1-1/2).(1-1/3).(1-1/4)...(1-1/50)
D= 2²/1.3 . 3²/2.4 . 4²/3.5 . 5²/4.6 . 6²/5.7
A = 13/21.2/11 + 13/21.9/11 + 8/21
= (13/21) + (13/21) + (8/21)
= (13 + 13 + 8)/21
= 34/21
B = (1 - 1/5)(1 - 2/5)(1 - 3/5)...(1 - 9/5)
= (4/5)(3/5)(2/5)(1/5)(0/5)(-1/5)(-2/5)(-3/5)(-4/5)
= 0
C = (1 - 1/2)(1 - 1/3)(1 - 1/4)...(1 - 1/50)
= (1/2)(2/3)(3/4)(4/5)...(49/50)
= 1/50
D = (2^2/1.3) * (3^2/2.4) * (4^2/3.5) * (5^2/4.6) * (6^2/5.7)
= (4/3) * (9/8) * (16/15) * (25/23) * (36/35)
= 0.979
1+1+1+1+1+1+1+1+1+1+1+11++1+11+1+1+1+1+1+11+11111++1+11+1+1+11+1+1+1+1+11+1+1+1+2+2
tìm các số nguyên x biết | x+2 | = 1/2-1/3+1/4/1/2+1/3-1/4+2/11-1/7+3/10/7/11-1/2+21/20
Giúp với ạ ! Mình đang cần lắm !
Tính A = (15/22 - 1/11) : 1/33 - (1/14 - 2/21) : 1/35 + 1 + 1/5 x (1/4 - 1/6 - 1) x 5/11
A = ( 15/22 - 2/22 ) : 1/33 - ( 6/84 - 8/84) : 1/35 + 1 + 1/5 . ( 3/12 - 2/12 - 12/12 ) . 5/11
A = 13/22 . 33 - (-1/42) . 35 + 1 + 1/5 . - 11/12 . 5/11
A = 39/2 - ( -5/6 ) + 1 + - 11/60 .5/11
A = 39/2 + 5/6 + 1 + (- 1/12)
A = 234/12 + 10 /12 + 12/12 + (-1/12)
A = 255/12
bài 1 : tính
a) 1+ 1/2 . (1+2) + 1/3 . (1 + 2 + 3) + 1/4 . (1+ 2 + 3 + 4) + .....+ 1/16 . (1 + 2 + 4 + .... + 16)
b) 1/68 . [( 3 10/11 - 1 ) : (21/22 - 1 ) : (33/34 - 1)
c) 0,4 + 2/9 - 2/11/1,4 + 7/9 - 7/11 : 1/3 + 0,25 - 1/5/1 1/6 + 0,875 - 0,7
bài 2: tìm x, biết
( 1/12 + 3 1/6 - 30,73 ) . x - 8 = ( 3/5 + 0,415 + 1/200 ) : 0,01
chú thích
[.] là dấu nhân
3 10/11 và 1 1/6 và 3 1/6 là hỗn số nha
thank so much
đây không phải bạn chửi bậy
Tính giá trị biểu thức sau :
A = ( 6 : 3/5 - 7/6 * 6/7 ) : ( 21/5 * 10/11 + 57/11 )
B = 59/10 : 3/2 - ( 7/3 * 9/2 - 2 * 7/3 ) : 7/4
C = ( 1 - 1/2 ) * ( 1- 1/3 ) * ( 1 - 1/4 ) * ( 1- 1/5 ) .............. ( 1 - 1/2003 ) * ( 1 - 1/2004 )
A = ( 6 : 3/5 - 7/6 * 6/7 ) : ( 21/5 * 10/11 + 57/11 )
A = ( 10 - 1 ) : ( 42/11 + 57/11)
A = 9 : 9
A = 1
B = 59 /10 : 3/2 - ( 7/3 * 9/2 - 2 * 7/3 ) : 7/4
B = 59/15 - ( 21/2 - 14/3 ) : 7/4
B = 59/15 - 35/6 : 7/4
B = 59/15 - 10/3
B = 3/5
thực hiện phép tính:
a. -1 / 21 + -1 / 28 - -1 / 21 - 3/14
b. ( -1/5 + 3/12 ) + -3/4
c.75% - 1 1/2 + 0,5 : 5/12
d.-4/11 . 2/5 + 6/11 . (-3)/10
e.( 2/3 - 1 1/2 ) : 4/3 + 1/2
f. 1/8.15 2/5 + 1 4/5. 1/8 - 17 1/5 . 1/8
g.1/7 - 8/7 : 8- 3 : 3/4 . (-2)2
giúp mình nha . Cảm ơn !