Chương III : Phân số
Các câu hỏi tương tự
Tính
\(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+\dfrac{1}{56}\)
Câu 1: Tính
a, A = 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + + 1/56 + 1/72
b, B = 1/5.6 + 1/6.7 + 1/7.8 + .... + 1/24.25
Cho mình hỏi:. Tính hợp lý :. a. -1/20 + -1/30 + -1/42 + -1/56 + -1/72 + -1/90. b. 5/1×2 + 4/1×11 + 3/11×2 + 1/15×1 + 13/15×4
Cảm ơn
\(\frac{1}{4.6}+\frac{1}{6.8}+\frac{1}{8.12}+...+\frac{1}{x\left(x+2\right)}=\frac{22}{1051}\)
Tính tổng sau: a) 1/2+1/6+1/12+1/20+1/30 b) 1/15+1/35+1/63+1/99+1/143 c) 1/6+1/12+1/20+1/30+1/42+1/56 d) 1/2+1/2^2+1/2^3+1/2^4+1/2^5 e) 1/7+1/7^2+1/7^3+...+1/7^100 f) 1+1/2*(1+2)+1/3*(1+2+3)+1/4*(1+2+3+4)+...+1/200*(1+2+3+..+200) g) (1/2+1)*(1/3+1)*(1/4+1)*..*(1/100+1) h) (1-1/2)*(1-1/3)*(1-1/4)*...*(1-1/2022) Giúp mk vs ạkkk
CMR 1/32+1/42+1/52+...+1/602<4/9
Tính P= -1/20 + -1/30 + -1/42 + -1/56 + -1/72 + -1/90
Tính nhanh
a. A = 3/2.5 + 3/5.8 +...+ 3/14.17+ 3/17.20
b. B = 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90
c. C= 42 /1.5 + 42/5.9 + 42/9.13 + ... + 42/45.49
bài 20 : tìm x dfrac{1}{1.2}+dfrac{1}{2.3}+...+ dfrac{1}{x.left(x+1right)}+dfrac{1}{2018.2019}bài 21: tìm xdfrac{x+1}{99}+dfrac{x+2}{98}+dfrac{x+3}{97}+dfrac{x+4}{96}-4bài 22: so sánha) dfrac{-1}{5}+dfrac{4}{-5} và 1b) dfrac{3}{5} và dfrac{2}{3}+dfrac{-1}{5}c) dfrac{3}{2}+dfrac{-4}{3} và dfrac{1}{10}+dfrac{-4}{5}d)dfrac{1}{2}+dfrac{1}{3}+dfrac{1}{4}+dfrac{1}{5}+dfrac{1}{6} và 2
Đọc tiếp
bài 20 : tìm x
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+ \(\dfrac{1}{x.\left(x+1\right)}\)+\(\dfrac{1}{2018.2019}\)
bài 21: tìm x
\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)+\(\dfrac{x+3}{97}\)+\(\dfrac{x+4}{96}\)=-4
bài 22: so sánh
a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\) và 1
b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)
c) \(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)
d)\(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2
a) ( 21/22 + 3/5 + -21/22 ) : 1 2/5 9/17 x 8/5 - 9/17 x 3/5 + 8/17
X - 3/10 = 7/15 x 3/15