Answer:
The expression which is a polynomial is:
![-6x^3+x^2-√(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/27iqaa1iwbxzrj6gab5d470akyle7xexko.png)
Explanation:
A polynomial expression is a expression of the form:
![f(x)=a_nx^n+a_(n-1)x^(n-1)+........+a_1x+a_0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qfy6ma4oy0769zb87d6xitb9a8gaw0set2.png)
where n belong to non-negative integers and
are real numbers.
1)
![4x^2-3x+(2)/(x)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b343xv3kr83l3v9b87cnt6zipojb3lsv4a.png)
This is not a polynomial because the third term:
has a negative poswer of x which violates the definition of polynomial.
2)
![-6x^3+x^2-√(5)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/27iqaa1iwbxzrj6gab5d470akyle7xexko.png)
In this each of the term satisfy the definition of polynomial and hence the expression is a polynomial expression.
3)
![8x^2+√(x)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2n5jp591u7wnrxm25wxtbdfjnjuaa8ye7u.png)
Here the second term is not a integer power and hence violate the definition of polynomial.
4)
![-2x^4+(3)/(2x)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lg1vvenqpq0w7sl2wj670vg6iujuxc1bfm.png)
which could also be written as:
![-2x^4+(3)/(2)x^(-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4bp7x5e4mpxr8b7tbi6hzt1kdmda30u29s.png)
Here the second term contain a negative power of x and hence is not a polynomial.