THU GỌN BIỂU THỨC SAU
\(\left(\frac{n-1}{1}+\frac{n-2}{2}+\frac{n-3}{3}+...+\frac{2}{n-2}+\frac{1}{n-1}\right):\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{n}\right)\)
Thu gọn
\(A=\frac{\left(1^4+\frac{1}{4}\right)\left(3^4+\frac{1}{4}\right)\left(5^4+\frac{1}{4}\right)...\left(2009^4+\frac{1}{4}\right)}{\left(2^4+\frac{1}{4}\right)\left(4^4+\frac{1}{4}\right)\left(6^4+\frac{1}{4}\right)...\left(2010^4+\frac{1}{4}\right)}\)
\(B=\frac{\left(a+2008\right)!+\left(a+2009\right)!}{\left(a+2008\right)!-\left(a+2009!\right)}\)
THU GỌN BIỂU THỨC SAU
\(\frac{2^3-1}{2^3+1}.\frac{3^3-1}{3^3+1}.\frac{4^3-1}{4^3+1}...\frac{n^3-1}{n^3+1}\)
thu gọn \(\left(\frac{3}{4}x^{n+1}-\frac{1}{2}y^n\right)\cdot2xy-\left(\frac{2}{3}x^{n+1}-\frac{5}{6}y^n\right)\cdot7xy\)
Cho \(n^4+\frac{1}{4}=\left(\left(n-1\right)n+\frac{1}{2}\right)\left(\left(n+1\right)n+\frac{1}{2}\right)\)
Thu gọn phân thức:
\(\frac{\left(1^4+\frac{1}{4}\right)\left(3^4+\frac{1}{4}\right)\left(5^4+\frac{1}{4}\right)...\left(13^4+\frac{1}{4}\right)}{\left(2^4+\frac{1}{4}\right)\left(4^4+\frac{1}{4}\right)\left(6^4+\frac{1}{4}\right)...\left(14^4+\frac{1}{4}\right)}\)
Rút gọn biểu thức:
\(B=\left(\frac{n-1}{1}+\frac{n-2}{2}+\frac{n-3}{3}+...+\frac{2}{n-2}+\frac{1}{n-1}\right):\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{n}\right)\) + \(\frac{1}{n}\) )
giúp mình với nhanh nha, mai nộp rồi!!!
1. Tính giá trị của biểu thức:
\(A=\left(\frac{m-n}{p}+\frac{n-p}{m}+\frac{p-m}{n}\right)\left(\frac{p}{m-n}+\frac{m}{n-p}+\frac{n}{p-m}\right)\)
biết \(m+n+p=0\)
2. Tính:
a) \(A=\frac{2^3+1}{2^3-1}.\frac{3^3+1}{3^3-1}.\frac{4^3+1}{4^3-1}...\frac{10^3+1}{10^3-1}\)
b) \(B=\frac{\left(1+\frac{1}{4}\right)\left(3^4+\frac{1}{4}\right)\left(5^4+\frac{1}{4}\right)...\left(9^4+\frac{1}{4}\right)}{\left(2^4+\frac{1}{4}\right)\left(4^4+\frac{1}{4}\right)\left(6^4+\frac{1}{4}\right)...\left(10^4+\frac{1}{4}\right)}\)
THU GỌN BIỂU THỨC SAU
\(\left(1-\frac{1}{2^2}\right)\left(1-\frac{1}{3^2}\right)\left(1-\frac{1}{4^2}\right)...\left(1-\frac{1}{n^2}\right)\)
(\(\frac{n-1}{1}+\frac{n-2}{2}+\frac{n-3}{3}+....+\frac{2}{n-2}+\frac{1}{n-1}\)):\(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+....+\frac{1}{n}\)