Question

Which algebraic expression among the following is a binomial?

• A. $5x+7x$
• B. $8a+9b$
• C. $17p+19q-21r$
• D. $23+15$

Answer 1

The correct option is B $8a+9b$

$\underset{–}{\text{Binomial Expression:}}$
A binomial expression is an algebraic expression having two unlike terms. For example, $2x+4,5xy+8y$ etc.

$\bullet$ In option (a.), we have $\underset{–}{5x+7x}$. It contains two like terms. After solving, it becomes one term as: $5x+7x=12x.$ Hence, it is $NOT$ binomial.

$\bullet$ In option (b.), we have $\underset{–}{8a+9b}$. It contains two unlike terms and hence, is a binomial.

$\bullet$ In option (c.), we have $\underset{–}{17p+19q-21r}$. It contains three unlike terms and hence, it is $NOT$ binomial.

$\bullet$ In option (d.), we have $\underset{–}{23+15}$. It contains two like terms. After solving, it becomes one term as: $23+15=38.$ Hence, it is $NOT$ binomial.


Therefore, option (b.) is the correct answer.