Q1. Which one is not a polynomial?

Here are the solutions to the multiple-choice questions:

Q1. Which one is not a polynomial?
A polynomial is an expression consisting of variables and coefficients, that involves only the operations of addition, subtraction, multiplication, and non-negative integer exponents of variables.

• a. $4x^2 + 2x - 1$: All exponents are non-negative integers (2, 1, 0). This is a polynomial.
• b. $y + \frac{3}{y} = y + 3y^{-1}$: The term $3y^{-1}$ has an exponent of $-1$, which is not a non-negative integer. This is not a polynomial.
• c. $x^3 - 1$: