Algebraic expressions are given. It is required to tell if they are polynomials, tell how many terms they have, and give reasons if they are not a polynomial.
Recall that polynomials are a monomial or a sum of monomials.
Recall also that monomials are a number, a variable, or a product of numbers and variables with whole-number exponents.
![(a)\text{ }x^2+4x-1](https://img.qammunity.org/2023/formulas/mathematics/high-school/ngns2ej14yn0nezxorkm5e04kl2uku6r11.png)
Notice that this satisfies the definition of a polynomial.
Hence, it is a polynomial and it has 3 terms.
![\begin{gathered} (b)\text{ }12(x^3-6)=12x^3-72 \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/euxtdpg86s3rzo75tzjvyyjpsurir0sw29.png)
Notice that this satisfies the definition of a polynomial.
Hence, it is a polynomial and it has 2 terms.
![(c)\text{ }(2)/(x)-3=2x^(-1)-3](https://img.qammunity.org/2023/formulas/mathematics/high-school/wa18fe99c27r4ao2ekd35c0a577tggrr56.png)
Notice that this expression does not satisfy the definition of a polynomial as it has a monomial with a negative number exponent variable, which is not a whole number.
Hence, it is not a polynomial, it has a term that has a variable with a negative exponent.
![(d)\text{ }9x^(40)](https://img.qammunity.org/2023/formulas/mathematics/high-school/jqdgw5etv0m4nfentx6njdw2mnehzf0y3i.png)
This is a polynomial with just 1 term.
![(e)\text{ }6x^3-4](https://img.qammunity.org/2023/formulas/mathematics/high-school/47stactzutl6tho6xpg5ixwix0gppfmzug.png)
This satisfies the definition of a polynomial.
Hence, it is a polynomial and it has 2 terms.
![(f)\text{ }3x^2-2x+1](https://img.qammunity.org/2023/formulas/mathematics/high-school/ehana9r8ljkq0c2jkcigbr7h40gici51x4.png)
This also satisfies the definition of a polynomial as it only has monomials with variables of whole-number exponents.
Hence, it is a polynomial and it has 3 terms.
![(g)\text{ }4x^2-3x+2x^(-2)](https://img.qammunity.org/2023/formulas/mathematics/high-school/pe5v7hy8a5y0i60qjwnc9d678eenxlci4y.png)
It is not a polynomial, it has a term that has a variable with a negative exponent.
![(h)\text{ }5+(1)/(2)x-√(3)x^2+x^3](https://img.qammunity.org/2023/formulas/mathematics/high-school/lfv0d67p6psioqg0as2h6v9ev1mugc3glx.png)
This also satisfies the definition of a polynomial as it only has monomials with variables of whole-number exponents.
Hence, it is a polynomial and it has 4 terms.
![(i)\text{ }3^(-1)x^2+5x-1](https://img.qammunity.org/2023/formulas/mathematics/high-school/ioon4o9knhno8916fytzg4y0zfr4eog1m9.png)
This also satisfies the definition of a polynomial as it only has monomials with variables of whole-number exponents.
Hence, it is a polynomial and it has 3 terms.