thấy câu này rất quen

a)\(y^3+y^2-9y-9\)

\(=\left(y^3+y^2\right)-\left(9y+9\right)\)

\(=y^2\left(y+1\right)-9\left(y+1\right)\)

\(=\left(y+1\right)\left(y^2-9\right)\)

\(=\left(y+1\right)\left(y^2-3^2\right)\)

\(=\left(y+1\right)\left(y-3\right)\left(y+3\right)\)

b)\(y^2+3y+2\)

\(=y^2+y+2y+2\)

=\(\left(y^2+y\right)+\left(2y+2\right)\)

=y(y+1)+2(y+1)

=(y+1)(y+2)

cho nhiều thế ai làm nổi

no one can do this because it to long

1)2x-6=5x-9

\(< =>2x-6-5x+9=0\)

<=>\(-3x+3=0\)

\(< =>-3x=-3\)

\(< =>x=1\)

S=\(\left\{1\right\}\)

\(\)2)\(4x^2-6x=0\)

\(< =>2x\left(2x-3\right)=0\)

\(< =>\left[{}\begin{matrix}2x=0\\2x-3=0\end{matrix}\right.\)

\(< =>\left[{}\begin{matrix}x=0\\x=\dfrac{3}{2}\end{matrix}\right.\)

S=\(\left\{0;\dfrac{3}{2}\right\}\)

dễ lắm nhưng dài quá sao giải nổi