Ta có: 2012=2011+1=x+1

\(A=x^5-2012x^4+2012x^3-2012x^2+2012x-2012\\ =x^5-\left(x+1\right)x^4+\left(x+1\right)x^3-\left(x+1\right)x^2+\left(x+1\right)x-\left(x+1\right)\\ =x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2+x-x-1\\ =-1\)

ủ4irir4101orerfd

Ta có : \(x=2011\Rightarrow x+1=2012\)

Khi đó :

\(x^{10}-2012x^9+2012x^8-2012x^7+....-2012x+2012\)

\(=x^{10}-\left(x+1\right)x^9+\left(x+1\right)x^8-\left(x+1\right)x^7+...-\left(x+1\right)x+x+1\)

\(=x^{10}-x^9-x^8+x^8+x^7-x^7-x^6+...-x^2-x+x+1\)

\(=1\)

x=2011 nên x+1=2012

\(P\left(x\right)=x^4-x^3\left(x+1\right)+x^2\left(x+1\right)-x\left(x+1\right)+x+1\)

\(=x^4-x^4-x^3+x^3+x^2-x^2-x+x+1=1\)

\(\frac{2011.2013-2011.2012}{2012.2011+2011.2013}\)

\(=\frac{2011.\left(2013-2012\right)}{2011.\left(2012+2013\right)}\)

\(=\frac{2011.1}{2011.4025}\)

\(=\frac{1}{4025}\)

bài này là bài Tính nha mọi người giải rõ ra giúp mik nha

\(\frac{2011x2013-2012x2011}{2012x2011+2011x2013}\)

\(=\frac{2011x\left(2013-2012\right)}{2011x\left(2012+2013\right)}\)

\(=\frac{2011x1}{2011x4025}\)

\(=\frac{1}{4025}\)

Thay 2012 = x + 1

\(B=x^{2011}-\left(x+1\right).x^{2010}+\left(x+1\right).x^{2009}+...-\left(x+1\right).x^2+\left(x+1\right).x-1\)

\(=x^{2011}-x^{2011}-x^{2010}+x^{2010}+x^{2009}-...-x^3-x^2+x^2+x-1\)

\(=x-1=2011-1=2010\)

Với x = 2011 => x + 1 = 2012

=> A = x¹⁰ - ( x + 1 )x⁹ + ( x + 1)x⁸ - ( x+ 1)x⁷ + ( x + 1 )x⁶ - ( x + 1 )x⁵+ ( x + 1 )x⁴ - ( x + 1 )x³ + ( x + 1)x² - ( x + 1 )x + 2012

        = x¹⁰ - x¹⁰ - x⁹ + x⁹ + x⁸ - x⁸ - x⁷ + x⁷+ x⁶- x⁶ - x⁵ + x⁵ + x⁴ - x⁴ - x³ + x³ + x² - x² - x + 2012

        = -x  + 2012

Thay x=2011 vào ta được: ( - 2011 ) + 2012 = 1