Tính nhanh: 113^2-26.113+13^2
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(2011\equiv1\left(mod2010\right)\Rightarrow2011^{2009}\equiv1\left(mod2010\right)\)
\(2009\equiv-1\left(mod2010\right)\Rightarrow2009^{2011}\equiv-1\left(mod2010\right)\)
\(\Rightarrow2009^{2011}+2011^{2009}\equiv0\left(mod2010\right)\Rightarrow2009^{2011}+2011^{2009}⋮2010\)
(x+1)(x+4)(x+2)(x+3)-8
= (x^2 +5x +4)(x^2 + 5x+6)-8
Đặt x^2 +5x +5= a
Ta có : (x^2 +5x+4)(x^2 +5x+6)-8
=(a-1)(a+1)-8
= a^2 -1 -8
=a^2 -9
= a^2 - 3^2
= (a-3)(a+3)
=(x^2 +5x+2)(x^2 + 5x+7)
ĐKXĐ: \(x\ne1\)
\(A=\frac{5x+1}{x^3-1}-\frac{1-2x}{x^2+x+1}-\frac{2}{1-x}\)
\(A=\frac{5x+1}{\left(x-1\right)\left(x^2+x+1\right)}-\frac{\left(1-2x\right)\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}+\frac{2\left(x^2+x+1\right)}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(A=\frac{5x+1-x+1+2x^2-2x+2x^2+2x+2}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(A=\frac{4x^2+4x+4}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(A=\frac{4\left(x^2+x+1\right)}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(A=\frac{4}{x-1}\left(x^2+x+1\ne0\right)\)
\(113^2-26.113+13^2\)
\(=\left(113-13\right)^2\)
\(=100^2\)
\(=10000\)