Voorbeelden van ontbinden in factoren:
`2 x^2+6 x=2 x(x+3)`
`text(-) x^2+4 x=x(text(-)x+4)=text(-)x(x-4 )`
`x^2+5 x+6 =(x+2)(x+3)`
`x^2-4 x-12 =(x+2)(x-6)` (Zie figuur.)
`x^3+4 x=x(x^2+4)`
Ontbind in factoren.
`2 x^2 + 10 x`
`text(-)2x^2+x`
`3x^3 -9x`
`x^2+5x+4`
`a^2-9a+8`
`a^2-17a+16`