Answer:
Step-by-step explanation:
We are given the following in the question:
Controller cost = $135
System cost = $2.50 per foot of pipeline
The total cost depends upon the length of Pole.
Let the system requires F feet of pipeline.
Total cost will be given by the equation:
is the required expression for total cost
F: feet of pipeline required
c(F): Total cost of installation
ANSWER
Emma is 44" tall
EXPLANATION
We have that David cast a shadow 42 inches long and he is 66 inches tall.
At that same place and time, Emma cast a shadow of 28 inches.
Since they are at the same spot and time, we can conclude that the ratio of their height to shadow must be the same.
Let Emma's height be x.
The ratio of David's shadow to height is:
42 : 66 or 42 / 66
For Emma, it is:
28 : x or 28 / x
That means that:
So, Emma is 44" tall.
The general formula for the distance between two points is
Anyway, if A and B have the same x or y coordinates, this formula can be simplified. For example, in this case the two points have the same x coordinate of -8, so the following part of the formula simplifies:
So, we're left with
but the square root of a square is the absolute value of the object being squared:
which is this case means
which is the correct length of the side.