Which of the following is not a polynomial? a. 4x2 + 2x - 1 b. y + rac3y c. x3 - 1

Here are the solutions to the multiple-choice questions:

Q1. Which one is not a polynomial?
A polynomial must have variables with non-negative integer exponents.

• a. $4x^2 + 2x - 1$: Exponents are $2, 1, 0$. This is a polynomial.
• b. $y + \frac{3}{y} = y + 3y^{-1}$: The exponent of $y$ in the second term is $-1$, which is not a non-negative integer. This is not a polynomial.
• c. $x^3 - 1$: Exponents are $3, 0$. This is a polynomial