12 / 3 = 4 and 18 / 3 = 6, you divide it by 3 because there are 3 sides in a triangle so on side is equal to 4a + 6b.
Answer: 83.3
Step-by-step explanation:
Formula :
(1)
(2)
Given : In a psychology class, 32 students have a mean score of 93.2 on a test.
By Using (2) , Sum of scores of 32 students = 93.2 x 32 =2982.4 (3)
Then 16 have a mean score of 63.4.
Again, By Using (2) , Sum of scores of 16 students = 63.4 x 16 =1014.4 (4)
Total students = 32+16 = 48
Add (3) and (4) , we get combined score of 48 students = 2982.4+ 1014.4
=3996.8
Now , by using (2) , the mean score of all of these students together

Hence, the mean score of all of these students together is 83.3.
Answer: D
Step-by-step explanation:
The x variable should be next to the 15 because it is your rate of change. It isn’t 25 because you add 25 because it’s initial fee. So it y for your total cost. y = 15x + 25
Answer:

Step-by-step explanation:

Answer:
Step-by-step explanation:
d^4-81
(d^2)^2-(9)^2
Using formula
(d^2+9)(d^2-9)