I think the answer should be 6,I just added the two fractions
Answer:
D
Step-by-step explanation:
N4=c
n times 4, n being a number of notebooks, would equal c, or the overall cost.
The graph is misleading because the year’s interval is not constant.
The first year to the second year, the gap is 1 year; in the second to the
third year, the gap is 2; in the third to the fourth year is 4; and the fourth
to the fifth year is 6.
Option A: z + 1
Option B: 6 + w
Option D: 
Solution:
Let us first define the polynomial.
A polynomial can have constants, variables, exponents and fractional coefficients.
A polynomial cannot have negative exponents, fractional exponents and never divided by a variable.
<u>To find which expressions are polynomial:</u>
Option A: z + 1
By the definition, z + 1 is a polynomial.
It is polynomial.
Option B: 6 + w
By the definition, 6 + w is a polynomial.
It is polynomial.
Option C: ![y^{2}-\sqrt[3]{y}+4](https://tex.z-dn.net/?f=y%5E%7B2%7D-%5Csqrt%5B3%5D%7By%7D%2B4)
![y^{2}-\sqrt[3]{y}+4=y^{2}-{y}^{1/3}+4](https://tex.z-dn.net/?f=y%5E%7B2%7D-%5Csqrt%5B3%5D%7By%7D%2B4%3Dy%5E%7B2%7D-%7By%7D%5E%7B1%2F3%7D%2B4)
Here, y have fractional exponent.
So, it is not a polynomial.
Option D: 
By the definition,
is a polynomial.
It is polynomial.
Hence z + 1, 6 +w and
are polynomials.