Đại số lớp 6
Các câu hỏi tương tự
Chứng minh:
C = \(\dfrac{1}{5}+\dfrac{1}{6}+\dfrac{1}{7}+...+\dfrac{1}{17}< 2\)
Bài 1: Cho A=\(\dfrac{1}{1.2}+\dfrac{1}{3.4}+\dfrac{1}{5.6}+...+\dfrac{1}{99.100}\)
a) Chứng minh: A=\(\dfrac{1}{51}+\dfrac{1}{52}+\dfrac{1}{53}+...+\dfrac{1}{100}\)
b) Chứng minh: A<\(\dfrac{5}{6}\)
chứng tỏ
\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\)+\(\dfrac{1}{7}\)+.....+\(\dfrac{1}{17}\)<2
Chứng tỏ rằng :dfrac{1}{101}+dfrac{1}{102}+...+dfrac{1}{299}+dfrac{1}{300}dfrac{2}{3}
Tính tích Adfrac{3}{4}.dfrac{8}{9}.dfrac{15}{16}...dfrac{899}{900}
Chứng tỏ rằng : dfrac{1}{5}+dfrac{1}{6}+dfrac{1}{7}+...+dfrac{1}{17} 2
Tính giá trị của biểu thức sau :
Mdfrac{1}{1.2.3}+dfrac{1}{2.3.4}+dfrac{1}{3.4.5}+...+dfrac{1}{10.11.12}
Đọc tiếp
Chứng tỏ rằng :\(\dfrac{1}{101}+\dfrac{1}{102}+...+\dfrac{1}{299}+\dfrac{1}{300}>\dfrac{2}{3}\)
Tính tích \(A=\dfrac{3}{4}.\dfrac{8}{9}.\dfrac{15}{16}...\dfrac{899}{900}\)
Chứng tỏ rằng : \(\dfrac{1}{5}+\dfrac{1}{6}+\dfrac{1}{7}+...+\dfrac{1}{17}< 2\)
Tính giá trị của biểu thức sau :
\(M=\dfrac{1}{1.2.3}+\dfrac{1}{2.3.4}+\dfrac{1}{3.4.5}+...+\dfrac{1}{10.11.12}\)
1.Tính nhanh
Adfrac{2}{7}+dfrac{-3}{8}+dfrac{11}{7}+dfrac{1}{3}+dfrac{1}{7}+dfrac{5}{-3}
Bdfrac{3}{17}+dfrac{-5}{13}+dfrac{-18}{35}+dfrac{14}{17}+dfrac{17}{-35}+dfrac{-8}{13}
Cdfrac{-3}{17}+(dfrac{2}{3}+dfrac{3}{17})
D(dfrac{-1}{6}+dfrac{5}{-12})+dfrac{7}{12}
2.a) Chứng tỏ:dfrac{1}{201}+dfrac{1}{212}+. . .+dfrac{1}{399}+dfrac{1}{400}
b)1 dfrac{1}{5}+dfrac{1}{6}+. . .+dfrac{1}{16}+dfrac{1}{17} 2
Đọc tiếp
1.Tính nhanh
A=\(\dfrac{2}{7}\)+\(\dfrac{-3}{8}\)+\(\dfrac{11}{7}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{7}\)+\(\dfrac{5}{-3}\)
B=\(\dfrac{3}{17}\)+\(\dfrac{-5}{13}\)+\(\dfrac{-18}{35}\)+\(\dfrac{14}{17}\)+\(\dfrac{17}{-35}\)+\(\dfrac{-8}{13}\)
C=\(\dfrac{-3}{17}\)+(\(\dfrac{2}{3}\)+\(\dfrac{3}{17}\))
D=(\(\dfrac{-1}{6}\)+\(\dfrac{5}{-12}\))+\(\dfrac{7}{12}\)
2.a) Chứng tỏ:\(\dfrac{1}{201}\)+\(\dfrac{1}{212}\)+. . .+\(\dfrac{1}{399}\)+\(\dfrac{1}{400}\)
b)1 < \(\dfrac{1}{5}\)+\(\dfrac{1}{6}\)+. . .+\(\dfrac{1}{16}\)+\(\dfrac{1}{17}\)< 2
BT3: Tìm x, biết:
7) \(\dfrac{-5}{17}+\dfrac{3}{17}\le\dfrac{x}{17}\le\dfrac{13}{17}+\dfrac{-11}{17}\)
8) \(\dfrac{2}{3}\left(\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{1}{3}\right)\le\dfrac{x}{18}\le\dfrac{7}{3}\left(\dfrac{1}{2}-\dfrac{1}{6}\right)\)
Cho :
A = \(\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{16}+\dfrac{1}{17}\)
Chứng minh A \(\notin\) N
CMR :
\(A=\dfrac{1}{5}+\dfrac{1}{6}+\dfrac{1}{7}+....+\dfrac{1}{17}< 2\)
BT5 : Chứng minh
2) \(\dfrac{3}{5}< \dfrac{1}{31}+\dfrac{1}{32}+\dfrac{1}{33}+....+\dfrac{1}{59}+\dfrac{1}{60}< \dfrac{4}{5}\)