Answer:
a 
Step-by-step explanation:
add all together
 
        
             
        
        
        
Answer:
Step-by-step explanation:
Let's label this triangle as triangle ABC.  Side AB is 18, side BC is 20 and side CA is 25 and the angle we are looking for is angle C.  Use the Law of Cosines to find the missing angle.  You have to use the Law of Cosines because in order to use the Law of Sines you have to have an angle given and we don't so we have no other options.  In our case,
 which for us looks like this:
 which for us looks like this:
 and
 and
 and
 and
 and
 and
 and
 and

Use the 2nd button and the cos button to find the missing angle.
Angle C = 45.4 which is, rounded to the nearest degree, 45°
 
        
             
        
        
        
Step-by-step explanation: 
To find the mean absolute deviation of the data, start by finding the mean of the data set. Find the sum of the data values, and divide the sum by the number of data values. Find the absolute value of the difference between each data value and the mean: |data value – mean|.
 
        
             
        
        
        
Answer:
4 cookies
Step-by-step explanation:
Let the number of cookies he sold be c and that of brownies be b.
Assuming that brownies and cookies are the only type of baked goods sold,
b +c= 10 -----(1)
Amount of money received= $20
b(cost of brownie) +c(cost of cookie)= $20
2.50b +1.25c= 20 -----(2)
From (1): b= 10 -c -----(3)
Substitute (3) into (2):
2.50(10 -c) +1.25c= 20
Expand:
2.50(10) +2.50(-c) +1.25c= 20
25 -2.50c +1.25c= 20
-1.25c +25= 20
Being constants to 1 side:
-1.25c= 20 -25
-1.25c= -5
c= -5 ÷(-1.25)
c= 4
Thus, Joe sold 4 cookies.
 
        
             
        
        
        
Answer:
1.5 per hour : 1.2 per hour
Step-by-step explanation:
The computation of the ratio is shown below:
For norma, the one pool would be
= 12  pools ÷ 8 hours
= 1.5 per hour
And for albert, the one pool would be 
= 9 pools ÷ 7.5 hours
= 1.2 per hour
So the ratio between them is 
1.5 per hour : 1.2 per hour