<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,

Answer:
line s
Step-by-step explanation:
The answer is Tuesday there will be 15 teachers for 179 students and 12 times 15 is 180
Answer: The average was 9 years old find the average age of both groups is 10 years old.
Step-by-step explanation:
Formula foe average : 
Given : The first group of students consists of 10 and their average age was 13 years old.
i.e.
(1)
The next group consisted of 30 students and their average was 9 years old.
i.e.
(2)
Then from (1) and (2) , the sum of both groups (first group and next group )students = 130+270 =400
Combined students of both groups (first and next group )= 10+30=40
Now , the average of both groups =

Hence, the average was 9 years old find the average age of both groups is 10 years old.