Answer:
<h3><em>
D. 880 = 45d + 70; 18 days.</em></h3>
Step-by-step explanation:
We are given fixed monthly charge = $70.
The cost of preschool per day = $45.
Number of days = d.
Total cost of d days = cost per day × number of days + fixed monthly charge.
Therefore, we get equation
880 = 45×d+70
<h3>880 = 45d +70.</h3>
Now, we need to solve the equation for d.
Subtracting 70 from both sides, we get
880-70 = 45d +70-70
810=45d
Dividing both sides by 45, we get

18=d.
Therefore,<em> 18 days Barry attended preschool last month.</em>
<em>Therefore, correct option is D option.</em>
<h3><em>
D. 880 = 45d + 70; 18 days.</em></h3>
Calculate the mean of each data set below. Can you find any shortcuts that allow you to find the mean without having to do much calculation? Homework help 6, 10, 6, 10 11, 12, 12, 13, 12 0, 5, 4, 8, 0, 7
Answer: To find the mean of the given observations. we just need to first find the sum of the given observations and the divide the calculate sum by the total number of observations.
So here:
Sum of of observations 
Number of observations = 15
Therefore, the mean 
It means the speed (velocity) was constant - the object traveled the same distance per time period throughout the graph.
Can you please please give me more information please thank you
You have the correct answer. Nice work. If you need to see the steps, then see below
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First we need to find the midpoint of H and I
The x coordinates of the two points are -4 and 2. They add to -4+2 = -2 and then cut that in half to get -1
Do the same for the y coordinates: 2+4 = 6 which cuts in half to get 3
So the midpoint of H and I is (-1,3). The perpendicular bisector will go through this midpoint
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Now we must find the slope of segment HI
H = (-4,2) = (x1,y1)
I = (2,4) = (x2,y2)
m = (y2 - y1)/(x2 - x1)
m = (4 - 2)/(2 - (-4))
m = (4 - 2)/(2 + 4)
m = 2/6
m = 1/3
Flip the fraction to get 1/3 ---> 3/1 = 3
Then flip the sign: +3 ----> -3
So the slope of the perpendicular bisector is -3
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Use m = -3 which is the slope we found
and (x,y) = (-1,3), which is the midpoint found earlier
to get the following
y = mx+b
3 = -3*(-1)+b
3 = 3+b
3-3 = 3+b-3
0 = b
b = 0
So if m = -3 and b = 0, then y = mx+b turns into y = -3x+0 and it simplifies to y = -3x
So that confirms you have the right answer. I've also used GeoGebra to help confirm the answer (see attached)