a/ \(=5x\left(x^2-2x+3\right)\)

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

a) \(5x^3-10x^2+15x=5x\left(x^2-2x+3\right)\)

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

\(a,=\left(x-y\right)\left(x+y\right)-\left(x+y\right)=\left(x+y\right)\left(x-y-1\right)\\ b,=\left(x+y\right)\left(x-5\right)\\ c,=5x^2\left(x-y\right)-10x\left(x-y\right)=5x\left(x-2y\right)\left(x-y\right)\\ d,=x^2-2xy=x\left(x-2y\right)\\ e,=\left(3x-2y\right)\left(9x^2+6xy+4y^2\right)\)

\(a,5x^3y-10x^2y^2\\=5x^2y(x-2y)\\b,x^4-y^4\\=(x^2)^2-(y^2)^2\\=(x^2-y^2)(x^2+y^2)\\=(x-y)(x+y)(x^2+y^2)\)

\(c,(x+5)^2-16\\=(x+5)^2-4^2\\=(x+5-4)(x+5+4)\\=(x+1)(x+9)\\d,7x(y-3)-14(3-y)\\=7x(y-3)+14(y-3)\\=(7x+14)(y-3)\\=7(x+2)(y-3)\\Toru\)

A

a) \(24x^2-4xy\)

\(=4x\left(6x-y\right)\)

b) \(5x^3-10x^2+5x-20xy^2\)

\(=5x\left(x^2-10x+5-20y^2\right)\)

nhầm câu b nha 

\(5x^3-10x^2+5x-20xy^2\)

\(=5x\left(x^2-2x+1-\left(2y\right)^2\right)\)

\(=5x\left(\left(x-1\right)^2-\left(2y\right)^2\right)\)

\(=5x\left(x-1-2y\right)\left(x-1+2y\right)\)

\(a,10x^2y-20xy^2=10xy\left(x-2y\right)\\ b,x^2-y^2+10y-25=x^2-\left(y^2-10y+25\right)=x^2-\left(y-5\right)^2=\left(x-y+5\right)\left(x+y-5\right)\\ c,x^2-y^2+3x-3y=\left(x-y\right)\left(x+y\right)+3\left(x-y\right)=\left(x-y\right)\left(x+y+3\right)\\ d,x^3+3x^2-16x-48=\left(x^3+3x^2\right)-\left(16x+48\right)=x^2\left(x+3\right)-16\left(x+3\right)=\left(x+3\right)\left(x^2-16\right)=\left(x+3\right)\left(x+4\right)\left(x-4\right)\)

\(e,9x^3+6x^2+x=x\left(9x^2+6x+1\right)=x\left(3x+1\right)^2\\ f,x^4+5x^3+15x-9=\left(x^4+5x^3-3x^2\right)+\left(3x^2+15x-9\right)=x^2\left(x^2+5x-3\right)+3\left(x^2+5x-3\right)=\left(x^2+3\right)\left(x^2+5x-3\right)\)

\(a,15x-5xy\\ =5x\left(3-y\right)\\ b,\left(x^2+1\right)^2-4x^2\\ =\left(x^2-x+1\right)\left(x^2+x+1\right)\\ c,x^2-10x-9y^2+25\\ =\left(x-5\right)^2-9y^2\\ =\left(x-9y-5\right)\left(x+9y-5\right)\)

hé lu ông zà

a) Ta có: \(x^2-3x+xy-3y\)

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

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

b) Ta có: \(x^3+10x^2+25x-xy^2\)

\(=x\left(x^2+10x+25-y^2\right)\)

\(=x\left(x+5-y\right)\left(x+5+y\right)\)

c) Ta có: \(x^3+2+3\left(x^3-2\right)\)

\(=4x^3-4\)

\(=4\left(x-1\right)\left(x^2+x+1\right)\)

\(=3x\left(x^2-5\right)\)

3x(x² - 5)