Answer:
(a)
Step-by-step explanation:
(a)The degree of a polynomial is the highest power of the unknown variable in the polynomial.
A polynomial is said to be in standard form when it is arranged in descending order/powers of x.
An example of a fourth degree polynomial is: 
We know the polynomial above is in standard form because it is arranged in such a way that the powers of x keeps decreasing.
(b)Polynomials are closed with respect to addition and subtraction. This is as a result of the fact that the powers do not change. Only the coefficients
change. This is illustrated by the two examples below:

The degrees do not change in the above operations. Only the number beside each variable changes. Therefore, the addition and subtraction of polynomials is closed.
Answer:
45.50° F
Step-by-step explanation:
As per Newton's law,

When T(t) is the final temperature
= Temperature of surrounding
= Initial temperature
t =duration of cooling
k = constant


Now take natural log on both the sides



4.6347 - 5.0434 = -5k

k = 0.0817

= 
= 155 (02935)
= 45.49 ≈ 45.50° F
Answer:
1/3 is closer to 0 than it is closer to -1
Step-by-step explanation:
<------------------(-1)--0---(1/3)----------------->
As you can see here, 1/3 is closer to 0 than -1
78 rounded to the nearest tenth is 80