Question

Answer 1

a) \(A=\dfrac{\left(x-1\right)\left(x-2\right)+6x-\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{x^2+2x}{\left(x-2\right)\left(x+2\right)}=\dfrac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{x}{x-2}\)

b) \(\left|x+1\right|=3\Leftrightarrow\left[{}\begin{matrix}x+1=3\\x+1=-3\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=2\left(ktm\right)\\x=-4\left(tm\right)\end{matrix}\right.\)

 

c) \(A=\dfrac{x}{x-2}=1+\dfrac{2}{x-2}\in Z\Rightarrow\left(x-2\right)\inƯ\left(2\right)=\left\{-2;-1;1;2\right\}\)

Kết hợp ĐKXĐ: 

\(\Rightarrow x\in\left\{0;1;3;4\right\}\)