Answer:
Step-by-step explanation:
a1 = 3(1) - 7 = - 4
a2 = 3(2) - 7 = -1
d = a2 - a1
d = -1 - (-4)
d = -1 + 4
d = 3
a60 = 3(60) - 7
a60 = 180 - 7
a60 = 173
n = 60
Sum = (a1 + a60) * n / 2
Sum = (-4 + 173) * 60/2
Sum = (169)*30
Sum = 5070
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Just to check, we'll use the second summation formula
d = 3
n = 60
a1 = -4
Sum = (2*a1 + (n - 1)*d )*n / 2
Sum = (2*(-4) + (60 -1)*3)* 60/2
Sum = (-8 + 59*3) * 30
Sum = (177 - 8)*30
Sum = 169 * 30
Sum = 5070
Same answer.
 
        
             
        
        
        
Answer:
x= 5.6
Step-by-step explanation:
we will need to put the information we currently have into an equation:
10•2•x= 112
then multiply 10•2 which equals 20...then the equation wil turn out like this:
20•x=112
now you will isolate the x... but how?? dividing 20 by itslef.. cancelling it out, and if you do one thing to the other side of the equation, you have to do it to the other...
20/20•x=112/20
you will end up with x= 122/20
you can use a calculator for this step, but  to practice long division... (check the screen shot thingie)
hope this helped !! ^^
 
        
             
        
        
        
Answer: See the description below.
The residuals are the difference between the actual and predicted values. Just subtract those values and plot the point.
Your points will be:
(2, 0)
(3, 4)
(4, -5)
(6, -1)
(7, 2)
        
             
        
        
        
Answer:
Step-by-step explanation:
It would be A, the first one.
 
        
                    
             
        
        
        
Answer:
Form an equation:
let x be the price of a shirt
Then, the price of a sweater would be x - 5
So you would have:
4(x - 5) + 3x = 200
simplify
4x - 20 + 3x = 200
7x - 20 = 200
add 20 to both sides
7x = 220
divide both sides by 7
x = about 31.43
That means the cost of the sweater would be 31.43 - 5 = 26.43