Answer:
C.) 
Step-by-step explanation:
The area formula:

Insert the values:

Use the distributive property:

:Done
Find the average :8.4+7.5+12.9+10.6 divided by four
Answer:
The answer is D.) infinitely many solutions mate
Answer:
The mean of the combined group is 76.67 ≈ 77
Step-by-step explanation:
- The sum of the grades in Tom's group is 20×70 = 1400
- The sum of grades in Alice's group is 10×90=900
- The sum of gradees in the combined group is =1400+900=2300
- Then the mean grade of the combined group is

where
- 2300 is the sum of the all grades in the combined group
- 30 is the total number of people in the group
Answer: 
Step-by-step explanation:
Since, the quotient of 6 and r = 
The sum of two and the quotient of 6 and r
= 
And, Five-sevenths of the sum of two and the quotient of 6 and r
= 
Thus, the required expression is, 