\(\left(\frac{1}{4\cdot5-1}-\frac{1}{7\cdot5-2}\right)\text{ : }\frac{40}{77}\)
\(=\left(\frac{1}{19}-\frac{1}{32}\right)\text{ : }\frac{40}{77}\)
\(=\frac{13}{608}\text{ : }\frac{40}{77}\)
\(=\frac{1001}{24320}\)
\(\frac{\left(\frac{1}{5}\right)^7.5^7+\left(\frac{9}{4}\right)^3:\left(\frac{3}{16}\right)^3}{2^7.5^2+129.2}\)
\(\left(1-\frac{2}{2.3}\right)\left(1-\frac{2}{3.4}\right)\left(1-\frac{2}{4.5}\right)......\left(1-\frac{2}{99.100}\right)\)
\(B=\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right)....\left(1-\frac{2}{99.100}\right)\)
Tính A biết :
\(A=\left(1-\frac{2}{2.3}\right)\left(1-\frac{2}{3.4}\right)\left(1-\frac{2}{4.5}\right)....\left(1-\frac{2}{98.99}\right)\left(1-\frac{2}{99.100}\right)\)
tính
\(\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right)...\left(1-\frac{2}{99.100}\right)\)
TÍNH HỢP LÝ
B=\(\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)\left(\frac{2}{4.5}-1\right)...\left(\frac{2}{2008.2009}-1\right)\)
\(\left(\frac{2}{2.3}-1\right)\left(\frac{2}{3.4}-1\right)\left(\frac{2}{4.5}\right)........\left(\frac{2}{n\left(n+1\right)}-1\right)\left(n\in N\ne0,n\ge2\right)\)
Tính tổng
S = \(\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right).....\left(1-\frac{2}{2015.2016}\right)\)
Tính giá trị biểu thức \(M=\left(1-\frac{2}{2.3}\right).\left(1-\frac{2}{3.4}\right).\left(1-\frac{2}{4.5}\right)....\left(1-\frac{2}{99.100}\right)\)
