5k chỗ nào vậy bạn

\(\frac{a}{a+ab+1}=\frac{ac}{ac+1+c}\)
\(\frac{bc}{b+bc+1}=\frac{ac}{1+ac+c}\)
=>A=1 

\(x^3+y^3=\left(x+y\right)\left(x^2-xy+y^2\right)\\ =\left(x+y\right)\left(x^2+y^2-xy\right)=2\left(10-xy\right)\)

nữa thì hết biết :v

\(\left|4x+4\right|+2x=3\)

\(\Leftrightarrow\left|4x+4\right|+2x-2x=3-2x\)

\(\Leftrightarrow\left|4x+4\right|=-2x+3\)

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

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

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

\(\Leftrightarrow\left[{}\begin{matrix}6x=-1\\2x=-7\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{6}\\x=-\dfrac{7}{2}\end{matrix}\right.\)

Vậy \(x=-\dfrac{1}{6}\) hoặc \(x=-\dfrac{7}{2}\)