[tex] \huge \boxed{\mathfrak{Answer} \downarrow}[/tex]
[tex]\huge \sf \: 3x + 11 + 2x[/tex]
The above expression will not become a trinomial because 3x + 11 + 2x will get simplified to -> 5x + 11 l, which is a binomial (an expression having 2 terms). To make it simpler, trinomials are formed if there are 2 or more variables or if the given variable is squared or cubed so that the expression cannot be easily simplified.
Explanation in numbers :-
[tex] \sf \: 3x + 11 + 2x \\ = \sf \: 3x + 2x + 11 \\ = \sf \: 5x + 11 \\ \bcancel = \bf \: a \: trinomial; \: it \: is \: a \: binomial[/tex]
