\(=2\left(\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+...+\dfrac{1}{15}-\dfrac{1}{17}\right)\)
\(=2\cdot\dfrac{14}{51}=\dfrac{28}{51}\)
\(=2\left(\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+...+\dfrac{1}{15}-\dfrac{1}{17}\right)\)
\(=2\cdot\dfrac{14}{51}=\dfrac{28}{51}\)
1/3x5+1/5x7+.....+1/13x15+1/15x17
Giúp với ạ
2/1x3 + 2/3x5 + 2/5x7 +...+2/15x17 + 2/17x19
tính phép tính : 1/3x5+1/5x7+1/7x9+......1/13x15+1/15x17
Tìm x biết:
(1/3x5+1/5x7+ 1/7x9+ 1/9x11+1/11x13+1/13x15+ 1/15x17+ 1/17x19+1/19x21)xX=9/7
Làm giúp mk nha, cảm ơn các bạn chi cần ghi đáp số thôi nhé
4/1x3+4/3x5+4/5x7+...+4/2009x2011
giup minh 4/1x3+4/3x5+4/5x7+4/7x9+....+4/17x19+4/19x21
K=\(\dfrac{4}{1x3}\)+\(\dfrac{4}{3x5}\)+\(\dfrac{4}{5x7}\)+...+\(\dfrac{4}{297x299}\)+\(\dfrac{4}{299x301}\)
Bài 1 Tính
a) A=1/2x3+1/3x4+1/4x5+1/5x6+...+1/99x100
b) B=2/3x5+2/5x7+2/7x9+...+2/99x101
c) C=3/3x5+3/5x7+3/7x9+...+3/99x101
d) D=4/3x8+4/8x13+4/13x8+...+4/53x58
Các bạn làm hộ giúp mình với cho mình lời giải
a.(x*2,4-4,2):x=1
b.1/1x3+1/3x5+1/5x7+...+1/x(x+2)
c.7/3+7/4-7/11 +5/7
5/3+5/9-5/11
Tính nhanh :\(\dfrac{2}{1X3}\) + \(\dfrac{2}{3X5}\) + \(\dfrac{2}{5X7}\) + ........ +\(\dfrac{2}{13X15}\) + \(\dfrac{2}{15X17}\) =
GHI RÕ CÁCH GIẢI RA HỘ MÌNH NHA
CẢM ƠN NHIỀU~~~~~~~