1/2 + 1/6 + 1/20 +........+1/110 + 1/132 =
1/2 + 1/2x3 + 1/3x4 + 1/4x5 +....+ 1/10x11 + 1/11x12
= 1/2 + 1/2 - 1/3 + 1/3 -1/4 + 1/4 - 1/5 +...+ 1/10 - 1/11 +1/11 - 1/12
= 1/2 + 1/2 - 1/12 = 1 - 1/12 = 11/12
Đáp số : 11/12
đúng mình cái nha
Tìm x (1/2 1/4):x=1/2+1/6+1/12+1/20+ ... 1/132
Tìm x biết (1/2+1/4+1/8+1/16):x=1/2+1/6+1/12+1/20+...+1/132
tìm x
[ 1/2 + 1/4 + 1/8 + 1/16 ] : x = 1/2 + 1/6 + 1/12 + 1/20 + .......+ 1/132
(1/2+1/4+1/8+1/16):x=1/2+1/6/+1/12+1/20+......+1/132
ai giải đc cảm ơn nhìu
a,1/6+1/12+1/20+1/132
b,1/15+1/35+1/63+1/99+1/143
Giúp mình với sáng mai kiểm tra rồi
| 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 = |
A=1/2+ 1/6+1/12+...+1/132
B= 5/1.4+ 5/4.7+5/7.10+...+5/97.100
( 1/2 + 1/4 + 1/8 + 1/16 ) : x = 1/2 + 1/6 + 1/12 + ... + 1/132
Tính nhanh tổng:1/2+ 1/6+ 1/12+...+1/110+1/132
