The vertex form of a quadratic function: y = a(x - h)² + k
vertex (h; k)
We have: y = 7(x - 4)² + v
vertex: (4; -2)
therefore: v = -2
Its two squares, so you need to start by finding the perfect roots that go into 117. If you need more help after that just comment :)
Basically adding a negative means subtracting and vice versa so
-13+-11=-13-11=-24
If its a gradient of -2 then y = c - 2x. if y = 1 when x = 1 then c = 1 + 2 so the equation would be y = 3 - 2x
Answer:
0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
In a given region, the number of tornadoes in a one-week period is modeled by a Poisson distribution with mean 2
Three weeks, so 
Calculate the probability that fewer than four tornadoes occur in a three-week period.
This is:

In which





Then

0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.