Answer:
17
Step-by-step explanation:
I: 2x+y=5
II:3x+2y=4
start by eliminating y
-2*I: -4x-2y=-10
II: 3x+2y=4
add both equations together
-2*I+II: -4x-2y+3x+2y=-10+4
-1x=-6
x=6
insert x=6 into I:
2*6+y=5
y=5-12
y=-7
so the solution is x=6, y=-7
You have to use distributive property.<span />
Answer:
x=11
Step-by-step explanation:
Simplifying X= 7+4
therefore x=11
Let X be the number of burglaries in a week. X follows Poisson distribution with mean of 1.9
We have to find the probability that in a randomly selected week the number of burglaries is at least three.
P(X ≥ 3 ) = P(X =3) + P(X=4) + P(X=5) + ........
= 1 - P(X < 3)
= 1 - [ P(X=2) + P(X=1) + P(X=0)]
The Poisson probability at X=k is given by
P(X=k) = 
Using this formula probability of X=2,1,0 with mean = 1.9 is
P(X=2) = 
P(X=2) = 
P(X=2) = 0.2698
P(X=1) = 
P(X=1) = 
P(X=1) = 0.2841
P(X=0) = 
P(X=0) = 
P(X=0) = 0.1495
The probability that at least three will become
P(X ≥ 3 ) = 1 - [ P(X=2) + P(X=1) + P(X=0)]
= 1 - [0.2698 + 0.2841 + 0.1495]
= 1 - 0.7034
P(X ≥ 3 ) = 0.2966
The probability that in a randomly selected week the number of burglaries is at least three is 0.2966