When finding a product means we are multiplying (3x+2)(3x+5) to multiply this we need to FOIL (3x)(3x) FIRST - [tex]9 x^{2} [/tex] (3x)(5) OUTER - 15x (2)(3x) INNER - 6x (2)(5) LAST - 10
so now we combine like terms - [tex]9 x^{2} +15x+6x+10[/tex] turns into [tex]9 x^{2} +21x+10[/tex]