Answer:
-13
Step-by-step explanation:
2x²+26x+156=0
x²+13x+78=0
x²+13x=-78
x²+13x+169/4=-143/4
(x+13/2)²=-143/4
x+13/2=(i√143)/2 or x+13/2=-(i√143)/2
x=(i√143)/2-13/2 or x=-(i√143)/2-13/2
(i√143)/2-13/2+(-(i√143)/2)-13/2=(i√143-13-i√143-13)/2=-26/2=-13
To get 17, you could do 20-3.
To get 41, you could do 50-9.
And to get 71, you could do 80-9.
Answer:
0.18203 = 18.203% probability that exactly four complaints will be received during the next eight hours.
Step-by-step explanation:
We have the mean during a time-period, which means that the Poisson distribution is used to solve this question.
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.
A service center receives an average of 0.6 customer complaints per hour.
This means that 
, in which h is the number of hours.
Determine the probability that exactly four complaints will be received during the next eight hours.
8 hours means that 
.
The probability is P(X = 4).
0.18203 = 18.203% probability that exactly four complaints will be received during the next eight hours.
Answer:
You could just replace all the given possible values of k in the inequality and see which ones are solutions, but let's solve this in a more interesting way:
First, remember how the absolute value works:
IxI = x if x ≥ 0
IxI = -x if x ≤ 0
Then if we have something like:
IxI < B
We can rewrite this as
-B < x < B
Now let's answer the question, here we have the inequality:
I-k -2I < 18
Then we can rewrite this as:
-18 < (-k - 2) < 18
Now let's isolate k:
first, we can add 2 in the 3 parts of the inequality:
-18 + 2 < -k - 2 + 2 < 18 + 2
-16 < -k < 20
Now we can multiply all sides by -1, remember that this also changes the direction of the signs, then:
-1*-16 > -1*-k > -1*20
16 > k > -20
Then k can be any value between these two limits.
So the correct options (from the given ones) are:
k = -16
k = -8
k = 0
