Câu 1 : (11/4.-5/9-4/9.11/4).8/33
Câu 2 : (17/28+18/29-19/30-20/31).(-5/2+1/4+1/6)
Câu 3 :(1/2+1).(1/3+1).(1/4+1) ... (1/99+1)
Câu 4 : 3/2^2.8/3^2.15/4^2 ... 899/30^2
Tính 1) 4/5 +13/18 2) 3/7 -11/8 3) -7/10 - -4/5 4) 3/20 -1/25 5) 2/3 - 5/6 6) 1/4 + -3/8 - 19/10 7) -9/10 - -7/18 8) 3/10 - 11/18 9) 3/5 -5/6 + -7/12 10) -4/9 - (-5 )/6 - 3/8
a.1/7.-3/8+-13/8
b.3/5.13/40-1/10.16/23
c.(-3/4+2/5):3/7+(3/5+1/4):3/7
d.7/8:(2/9-1/8)+7/8:(1/6-5/12)
e.(-2/3+3/7):4/5+(-1/3+4/7):4/5
Giúp mình với..
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
Tính :
C= 1/5+1/10+1/20+1/40+...+1/1280D= 2/1*3+2/3*5+2/5*10+2/7*9+2/9*11+2/11*18+2/13*15E= 4/3*7+4/7*11+4/11*15+4/15*19+4/19*23+4/23*27G= 1/2+1/6+1/12+1/20+1/30+1/42+...+1/110H= 3/1*2+3/2*3+3/3*4+3/4*5+...+3/9*10Giúp mk nha *.*
3/10--2/5-11/-20
3/4+-5/6-7/18
5/14-7/-8+-1/2
1/2+-1/4+2/3+-5/6
-12/18 + (-21)/35
-3/21 + 6/42
-18/24 + 15/21
1/6 + 2/5
3/5 + (-7)/4
(-2) + (-5)/8
1/-8 + (-5)/9
4/13 + 12/39
1/21 + 1/28
-3/29 + 16/58
8/40 + (-36)/45
-8/18 + (-15)/27
13/30 + (-1)/5
2/21 + 1/28
5 + (-3)/4
18/24 + 45/-10
a) 3/13 + 7/12 - 10/13 + 5/12 | d) -5/10 + 12/28 - 3/27 - 7/18 + 20/35 |
b) 15/24 - 6/26 + 28/48 - 30/39 + 10/24 | e) 1/56 + 1/72 + 1/90 + 1/110 + 1/132+ 1/156 = |
c) -1/2 + 3/7 - 1/9 - 7/18 + 4/7 = |
E=1×2×3+2×3×4×3×4×5+...+18×19×20
G=2×4×6+4×6×8+6×8×10+...-18×20×22
H=1×3×5+3×5×7+5×7×9+17×19×21