D=\(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{198}+\frac{1}{199}}{\frac{1}{199}+\frac{2}{198}+\frac{3}{197}+...+\frac{198}{2}+\frac{199}{1}}\)
Tính tỉ số A và B , biết rằng :
\(A=\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{200}\)
\(B=\frac{1}{199}+\frac{2}{198}+\frac{3}{197}+...+\frac{198}{2}+\frac{199}{1}\)
Tính A/B biết ; A=1/2+1/3+1/4+...+1/100 B= 1/199+2/198+3/197+...+197/3+198/2+199/1
CMR: \(14< \frac{2}{1}.\frac{4}{3}.\frac{6}{5}....\frac{200}{199}< 20\)
Tính A/B biết:
A=1/2 +1/3 1/4 1/5 ..... 1/200
B1/199+ 2/198+ 3/197 + ..........................+ 198/2 +199/1
Cho A=\(\frac{2}{1}.\frac{4}{3}.\frac{6}{5}...\frac{200}{199}CMR:14< A< 20\)
Rút gọn các biểu thức sau :
\(\frac{1}{3}-\frac{1}{3^2}+\frac{1}{3^3}-...-\frac{1}{3^{198}}+\frac{1}{3^{199}}\)
\(\frac{2}{5^1}+\frac{3}{5^2}+\frac{4}{5^3}+...+\frac{100}{5^{99}}\)
\(\frac{1}{2^2-1}+\frac{1}{3^2-1}+\frac{1}{4^2-1}+...+\frac{1}{200^2-1}\)
E=1/2+1/3+1/4+...+1/200
199/1+198/2+197/3+...+1/199
tính nhanh
1/2*3 + 1/6*5 + 1/10*7 + 1/14*9+..+ 1/198*101