\(x^3-2x^2+x\)

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

\(=x\left(x-1\right)^2\)

\(\hept{\begin{cases}3x-y=1\\6x-2y=5\end{cases}}\)

\(\Leftrightarrow\)\(\hept{\begin{cases}6x-2y=2\\6x-2y=5\end{cases}}\)(vô nghiệm)

Vậy PT vô nghiệm

Nếu sai thì sorry..

Mk k chắc là đúng đây nha, sai thông cảm :)

\(\hept{\begin{cases}3x-y=1\\6x-2y=5\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}3x=y\\2\left(3x\right)-2y=5\end{cases}}\)

\(2y-2y=5\)

\(0=5\)

=> k tìm đc x, y t/m 

3a)

\(A=x^3-9x^2+27x-27\)

\(=\left(x-3\right)^3=\left(1-3\right)^3=-8\)

1a) \(36a^4-y^2\)

\(=\left(6a^2\right)^2-y^2\)

\(=\left(6a^2+y\right)\left(6a^2-y\right)\)

4x² - 6x

= 2x . (2x - 3)

Trả lời:

a, \(\left(xy+4\right)^2-4\left(x+y\right)^2\)

\(=\left(xy+4\right)^2-\left[2\left(x+y\right)\right]^2\)

\(=\left(xy+4\right)^2-\left(2x+2y\right)^2\)

\(=\left(xy+4-2x-2y\right)\left(xy+4+2x+2y\right)\)

\(=\left[\left(xy-2x\right)-\left(2y-4\right)\right]\left[\left(xy+2x\right)+\left(2y+4\right)\right]\)

\(=\left[x\left(y-2\right)-2\left(y-2\right)\right]\left[x\left(y+2\right)+2\left(y+2\right)\right]\)

\(=\left(y-2\right)\left(x-2\right)\left(y+2\right)\left(x+2\right)\)

b, \(2x-\sqrt{x}=2.\sqrt{x}.\sqrt{x}-\sqrt{x}=\sqrt{x}.\left(2\sqrt{x}-1\right)\)