Answer:
The slope of line is 0 given points (2,8)(7,8)
Step-by-step explanation:
We need to find slope of line given points (2,8),(7,8)
The formula used to find slope of line is: 
We are given:

Finding slope using formula:

So, the slope of line is 0
<u>Part a)</u>
Given the expression

Apply exponent rule: 
∵ 
Rewrite 81 as 3 · 27
Rewrite 54 as 2 · 27

Factor out the common term: 27m³n
Therefore,

<u>Part B)</u>
Given the expression

Apply exponent rule: 

Rewrite as

Factor out common term 5y²x²z

Therefore,

0.12 is the correct answer