tinh gia tri bieu thuc (2/3x1/5+1/5) : (2/3:1/5-1/5) / 1/2 - 21/47
1/1x1/2+1/2x1/3+1/3x1/4+1/4x1/5+1/5x1/6
tính nhanh
a)\(\frac{2}{3}:\frac{5}{7}\cdot\frac{5}{7}:\frac{2}{3}+1934\)
b) \(\frac{1}{5}:\frac{1}{3}\cdot\frac{1:3}{1:5}+1996\)
a, 1/2 x 1/3 + 1/3x1/4 +1/4 x 1/5 + 1/5 x 1/6 + 1/6 x 1/7 + 1/7 x 1/8 + 1/8 x 1/9 = ?
Tính:
a) 11/3-2/3x5/6. b) 13/2+7/6:2/3
c) 28/9-3/4+1/3. d) 5/8:2/3x1/5
2 1/3x1/5+7/3=,,,
cho em câu trả lời cuối cùng
a)[1-1/2]x[1-1/3]x[1-1/4]x..........[1-1/18]x[1-1/19]x[1-1/20]
b)1/1/2x1/1/3x1/1/4x1/1/5........x1/1/2005x1/1/2006x1/1/2007
tính nhanh :
`2/3:5/7xx5/7:2/3+1934`
1/3x1/6x1/9 1/3x1/6:1/9 1/3:1/6x1/9
Giúp mk giả bài toán này nha!!!!!!!!