Final answer:
Expression d) x+ is not a polynomial since it is incomplete and does not fit the standard structure of a polynomial with non-negative integer exponents and real number coefficients. All other options provided can be considered as polynomials.
Step-by-step explanation:
The student has asked which expression is not a polynomial.
To be considered a polynomial, an expression must consist of a finite sum of terms including variables raised to non-negative integer exponents, and real number coefficients. Let's review each option:
- a) х - This is a polynomial as it can be written as x^1, with a coefficient of 1.
- b) 5x - 2 - This expression also qualifies as a polynomial as it is a linear function with a degree of 1.
- c) fx - Assuming 'f' stands for a function of x, this expression cannot be determined without more information. However, if 'f' is treated as a constant coefficient, then fx would be a polynomial.
- d) x+ - This expression is not clear as presented; 'x+' is incomplete and does not define a polynomial or any standard mathematical expression.
Based on the assumption that typos should be ignored and every other expression except for 'd' could be considered a polynomial, the response would be option d) x+, as it does not represent a recognizable polynomial expression.