Question

Which of the following expressions has a constant?

• A. $3x$
• B. $x+5$
• C. $y$
• D. $ab+2a$

Answer 1

The correct option is B $x+5$

A constant is that whose value is fixed. It never changes.

In the expression $x+5$, $5$ is a constant.

However in the expressions $3x$, $y$ and $ab+2a$, there are no constants.
(Note that, 3 in 3x is the coefficient of x, and not a constant.)