I need help I’ve been having trouble with this chapter for about a week

Given:
[tex]3x^2+20x+33[/tex]Find-:
Factorization of the equation.
Sol:
A simple method of factorization is to multiply in first and last order then break it down into parts to make the middle number then.
[tex]\begin{gathered} =3\times33 \\ =99 \end{gathered}[/tex]
The factor of 99 is:
So take factor :
[tex]\begin{gathered} 11\text{ and \lparen3}\times3) \\ \\ 11\text{ and 9} \end{gathered}[/tex]Factorization of the equation is:
[tex]\begin{gathered} =3x^2+20x+33 \\ \\ =3x^2+11x+9x+33 \end{gathered}[/tex]