Cho x = 2005. Tính giá trị của biểu thức:
\(x^{2005}-2006.x^{2004}+2006.x^{2003}-2006.x^{2002}+...-2006.x^2+2006x-1\)
so sánh: \(\left(\frac{2006-2005}{2006+2005}\right)^2\) và \(\frac{2006^2-2005^2}{2006^2+2005^2}\)
\(\frac{a+2006}{a-2006}=\frac{b+2005}{b-2005}chứngminh\frac{a}{b}=\frac{2006}{2005}\)
Cho \(\frac{a}{b}=\frac{c}{d}\). Chứng minh:
a) \(\frac{\left(a-b\right)^3}{\left(c-d\right)^3}=\frac{3a^2+2b^2}{3c^2+2d^2}\)
b)\(\frac{4a^4+5b^4}{4c^4+5d^4}=\frac{a^2b^2}{c^2d^2}\)
c)\(\left(\frac{a-b}{c-d}\right)^{2005}=\frac{2a^{2005}-b^{2005}}{2c^{2005}-d^{2005}}\)
d)\(\frac{2a^{2005}+5b^{2005}}{2c^{2005}+5d^{2005}}=\frac{\left(a+b\right)^{2005}}{\left(c+d\right)^{2005}}\)
e)\(\frac{\left(20a^{2006}+11b^{2006}\right)^{2007}}{\left(20a^{2007}-11b^{2007}\right)^{2006}}=\frac{\left(20c^{2006}+11d^{2006}\right)^{2007}}{\left(20c^{2007}-11d^{2007}\right)^{2006}}\)
f)\(\frac{\left(20a^{2007}-11c^{2007}\right)^{2006}}{\left(20a^{2006}+11c^{2006}\right)^{2007}}=\frac{\left(20b^{2007}-11d^{2007}\right)^{2006}}{\left(20b^{2006}+11d^{2006}\right)^{2007}}\)
Cho a/b=c/d chứng tỏ (2005.a-2006.b)/(2006.c-2007.d)=(2005.c-2006.d)/(2006.a-2007.b)
cho x,y,z thỏa mãn |x+17/3|+|y-2000/1999|+|z-2005|=0 Tính x+y
giải giúp mình nha !
so sánh \(\sqrt{2005+2006}và\sqrt{2005}+\sqrt{2006}\)
So sánh:
\(A=\dfrac{1999^{1999}+1}{1999^{1998}+1}\) ; \(B=\dfrac{1999^{2000}+1}{1999^{1999}+1}\)
Giúp với!
So sánh: C=\frac{1999^2000+1/1999^1999+1} và D=\frac{1999^1999+1/1999^1998+1}