Answer:
x = 2 ±i
Step-by-step explanation:
x^2 = 4x-5
Subtract 4x from each side
x^2 - 4x = 4x-5 -4x
x^2 - 4x= -5
Complete the square
Take the coefficient of the x term, divide by 2 and square it
-4/2 =2 2^2 =4
Add 4 to each side
x^2 -4x+4 = -5 +4
The left side is (x-coefficient of the x term/2)^2
(x-2)^2 = -1
Take the square root of each side
sqrt((x-2)^2) = sqrt(-1)
x-2 = ±i
Add 2 to each side
x-2+2 = 2 ±i
x = 2 ±i
Answer:
D.
Step-by-step explanation:
2 is it's length while in the perinthesis is x for its length plus the width which is doubled, explained by the x.
Answer:
a

b

Step-by-step explanation:
From the question we are told that
The mean value is 
The standard deviation is 
Considering question a
The sample size is n = 9
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the probability that the sample mean hardness for a random sample of 9 pins is at least 51 is mathematically represented as



=> 
From the z table the area under the normal curve to the left corresponding to 2.5 is

=> 
=> 
Considering question b
The sample size is n = 40
Generally the standard error of the mean is mathematically represented as

=>
=> 
Generally the (approximate) probability that the sample mean hardness for a random sample of 40 pins is at least 51 is mathematically represented as

=> 
=> 
From the z table the area under the normal curve to the left corresponding to 5.2715 and
=> 
So

=> 
Answer: 0.31
Step-by-step explanation:
Let A denotes the event that the students report drinking alcohol and B denotes the students report using some type of tobacco product .
Given : P(A) =0.84 ; P(B)=0.33 and P(A∪B)=0.86
We know that 
Then, the probability that the student both drunk alcohol and used tobacco in the past month is given by :-

Hence, the probability that the student both drunk alcohol and used tobacco in the past month = 0.31
Answer:
he gets more money then he had to start with
Step-by-step explanation: