Answer:

Step-by-step explanation:
The equation of a horizontal parabola in the standard form:

(h, k) - vertex
if a > 0, then open right
if a < 0, then open left
We have the vertrex (-1, -3) and the parabola is open left (a < 0).
Therefore the equation of a given parabola could be:

Every time x is added by one, y is added by three.
Answer:
It takes less time sending 5 letters the traditional way with a probability of 36.7%.
Step-by-step explanation:
First we must take into account that:
- The traditional method is distributed X ~ Poisson(L = 1)
- The new method is distributed X ~ Poisson(L = 5)

Where L is the intensity in which the events happen in a time unit and x is the number of events.
To solve the problem we must calculate the probability of events (to send 5 letters) in a unit of time for both methods, so:
- For the traditional method:

- For the new method:

According to this calculations we have a higher probability of sending 5 letters with the traditional method in a unit of time, that is 36.7%. Whereas sending 5 letters with the new method is less probable in a unit of time. In other words, we have more events per unit of time with the traditional method.
Answer:

Step-by-step explanation:
we know that
Triangles BDR and QDC are similar, because QC and BR are parallel lines
If two figures are similar, then the ratio of its corresponding sides is equal and is called the scale factor
In this problem

substitute the values







Answer:
x = -16
Step-by-step explanation:
52= 1/2x+15−3.25x−7
Combine 1/2x and −3.25x to get −11/4 x.
52= −11/4x+15−7
Subtract 7 from 15 to get 8.
52=−11/4x+8
Swap sides so that all variable terms are on the left hand side.− 11/4x+8=52
Subtract 8 from both sides.
− 11/4x=52−8
Subtract 8 from 52 to get 44.
−11/4 x=44
Multiply both sides by − 4/11
the reciprocal of − 11/4
x=44(−4/11)
Express 44(−4/11 ) as a single fraction.
x= 44(−4)
Multiply 44 and −4 to get −176.
x= −176/11
Divide −176 by 11 to get −16.