Answer:
-7
Step-by-step explanation:
You use the quadratic formula of 
to get:
a = 1
b = 7
c = -13
then you plug that into x= (-b ± √b²-4ac)/(2a) :
x= ( -7 ± √7²- 4(1)(-13) )/(2(1))
The sum of these two x values turns out to be:
there are 10 numbers you want either a 4 or 7 ( 2 numbers)
so probability is 2/10 which reduces to 1/5
Answer:
18 is the greatest common factor between those
Answer:
μ = 1 The firm expects that one oil exploration will be successful.
v(x)= 0.9
Step-by-step explanation:
The first step is to define the random variable x as:
x: number of oil explorations being succesful
Then x can be take this values:
x = 0 , x =1 ... x =10
x is a binomially distributed random variable with parameters.
p = 0.1 and n=10
And the mean or the expected value of x is:
μ = E(x) = np
Then μ = 10*0.1 = 1
And the variance of x is:
V(x) = np(1-p)
V(x) = 10(0.1)(1-0.1)= 0.9
4x-3y=17......(1)
5x+4y=60......(2)
Multiply equation (1) by 4 and equation (2) by 3:-
16x - 12y = 68
15x + 12y = 180
Adding these 2 equations:_
31x = 248
x = 248/31 = 8
Now substitute x = 8 in equation (1):-
4(8) - 3y = 17
32-3y = 17
-3y = -15
y = -15/-3 = 5
So solution is x=8,y=5
