tính \(\frac{A}{B}\)biết;
A=\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{17.18}+\frac{1}{19.20}\)và
B =\(\frac{1}{11}+\frac{1}{12}+\frac{1}{13}+...+\frac{1}{19}+\frac{1}{20}\)
tính B
B=\(\frac{\left(\frac{3}{2}\right)^3.\left(-\frac{3}{4}\right)^2.\left(-1\right)^{2012}}{36.\frac{1}{5}.\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
A=\(\frac{10^{2006}+1}{10^{2007}+1}\) và B=\(\frac{10^{2007}+1}{10^{2008}+1}\)
\(\text{cho A=(2x+3).(x-1)-(x+1).(2x-5)-2}\)
\(\text{B= (x-4).(x-2)-(3x+1),(1/3x-2)+2}\frac{1}{3}-x-10\)
Tìm công thức liên hệ Avà B
Cho \(\frac{a}{b}=\frac{c}{d}\)CMR: \(\frac{bz-cy}{a}=\frac{cx-az}{b}=\frac{ay-bx}{c}\)
\(\frac{3a-2b}{5}=\frac{2c-5a}{3}=\frac{5b-3c}{2}\)và \(a^2+275=bc\)
tính D=(\(\frac{1}{4}-1\)).(\(\frac{1}{9}-1\))...(\(\frac{1}{100}-1\))
\(\left(\frac{2}{25}-1,008\right):\frac{4}{7}:\left[\left(3\frac{1}{4}-6\frac{5}{9}\right).2\frac{2}{17}\right]\)
Tính giá trị của biểu thức:
\(A=\frac{2014x+2013y}{2014x-2013y}\).Biết \(\frac{x}{y}=\frac{2}{3}\)