Which of the following is NOT a Monomial?

Which of the following is NOT a Monomial?

• A. 3x
• B. 2x^2
• C. x + 1
• D. 7

Answer: (C)

Monomials are single-term expressions: a coefficient times a variable raised to a nonnegative integer power. The pieces 3x and 2x^2 are each a single term, and 7 is a constant term, which is also a single term (7 can be viewed as 7·x^0). The expression x + 1 has two terms joined by a plus, so it isn’t a monomial. Therefore, x + 1 is not a monomial.

Monomials are single-term expressions: a coefficient times a variable raised to a nonnegative integer power. The pieces 3x and 2x^2 are each a single term, and 7 is a constant term, which is also a single term (7 can be viewed as 7·x^0). The expression x + 1 has two terms joined by a plus, so it isn’t a monomial. Therefore, x + 1 is not a monomial.