Question

Mn giúp em với

Answer 1

\(a,A=\dfrac{2x\left(x-1\right)+2\left(x^2+x+1\right)-4x^2}{x\left(x-1\right)\left(x^2+x+1\right)}\\ A=\dfrac{2x^2-2x+2x^2+2x+2-4x^2}{x\left(x-1\right)\left(x^2+x+1\right)}\\ A=\dfrac{2}{x\left(x^3-1\right)}\\ b,x=2\Leftrightarrow A=\dfrac{2}{2\left(8-1\right)}=\dfrac{2}{14}=\dfrac{1}{7}\)