Tính A=\(\frac{\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{101\cdot400}}{\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+...+\frac{1}{299\cdot400}}\)
\(\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{299\cdot400}\)chứng minh rằng \(\frac{1}{299}\left(\left(1+\frac{1}{2}+...+\frac{1}{101}\right)-\left(\frac{1}{300}+\frac{1}{301}+...+\frac{1}{400}\right)\right)\)=\(\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{299\cdot400}\)
Tính \(\frac{A}{B}\), biết rằng :
\(A=\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{101\cdot400}\)
\(B=\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+...+\frac{1}{299\cdot400}\)
Tính \(\frac{A}{B}\), biết rằng :
\(A=\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{101\cdot400}\)
\(B=\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+...+\frac{1}{299\cdot400}\)
A=\(\frac{1}{1\cdot300}\)+\(\frac{1}{2\cdot301}\)+...+\(\frac{1}{101\cdot400}\)tinh \(\frac{A}{B}\)
B=\(\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+...+\frac{1}{299\cdot400}\)
1> Tính A/B
A= \(\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+.....+\frac{1}{101\cdot400}\)
B = \(\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+.....+\frac{1}{299\cdot400}\)
2> Cho a,b thộc N*
CMR :\(\frac{a}{b}+\frac{b}{a}\)lớn hơn hoặc bằng 2
nhanh nha đang cần gấp
thanks so much
a) Rút gọn:
\(\frac{\frac{1}{1\cdot300}+\frac{1}{2\cdot301}+\frac{1}{3\cdot302}+...+\frac{1}{101\cdot400}}{\frac{1}{1\cdot102}+\frac{1}{2\cdot103}+\frac{1}{3\cdot104}+...+\frac{1}{299\cdot400}}\)
b) CMR: \(1\cdot3\cdot5\cdot7\cdot9\cdot...\cdot197\cdot199\)= \(\frac{101}{2}\cdot\frac{102}{2}\cdot\frac{103}{2}\cdot...\cdot\frac{200}{2}\).
c) Cho: A=\(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+...+\frac{1}{199\cdot200}\).
B=\(\frac{1}{101\cdot200}+\frac{1}{102\cdot199}+...+\frac{1}{199\cdot102}+\frac{1}{200\cdot101}\).
d) Tìm số tự nhiên n lớn nhất có ba chữ số sao cho n chia 8 dư 7,chia 31 dư 28.
e) Tìm số nguyên tố \(\overline{ab}\) (a>0>b),sao cho \(\overline{ab}-\overline{ba}\)là số chính phương.
C = \(\frac{1+\frac{1}{3}+\frac{1}{3^2}+....+\frac{1}{3^{100}}}{1+\frac{1}{3}+......+\frac{1}{3^{101}}}\)
D = \(\frac{1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^{101}}}{1+\frac{1}{3}+........+\frac{1}{3^{102}}}\)
ai lam ho minh voi so sanh nha
Tính \(H=\left[101-\frac{1}{9}-\frac{2}{10}-\frac{3}{11}-...-\frac{101}{109}\right]:\left[\frac{1}{45}+\frac{1}{50}+\frac{1}{55}+...+\frac{1}{545}\right]\)