Question

Which of the following is a trinomial?

• A. $x$
• B. $ab$
• C. $a+b$
• D. $x^2+2xy+y^2$

Answer 1

The correct option is D $x^2+2xy+y^2$

Among the given options,$x$ has one term in it, and it is a monomial.
$ab$ has two variables. But the number of terms is just one. Hence it is a monomial.
$a+b$ is a binomial as it has two unlike terms.
$x^2+2xy+y^2$ has three unlike terms and hence it is a trinomial.