7 Hours. 315 divided by 45 equals 7.
Answer:
(x-12) (x+7)
Step-by-step explanation:
Answer:

Step-by-step explanation:
This is a conditional probability exercise.
Let's name the events :
I : ''A person is infected''
NI : ''A person is not infected''
PT : ''The test is positive''
NT : ''The test is negative''
The conditional probability equation is :
Given two events A and B :
P(A/B) = P(A ∩ B) / P(B)

P(A/B) is the probability of the event A given that the event B happened
P(A ∩ B) is the probability of the event (A ∩ B)
(A ∩ B) is the event where A and B happened at the same time
In the exercise :



We are looking for P(I/PT) :
P(I/PT)=P(I∩ PT)/ P(PT)

P(PT/I)=P(PT∩ I)/P(I)
0.904=P(PT∩ I)/0.025
P(PT∩ I)=0.904 x 0.025
P(PT∩ I) = 0.0226
P(PT/NI)=0.041
P(PT/NI)=P(PT∩ NI)/P(NI)
0.041=P(PT∩ NI)/0.975
P(PT∩ NI) = 0.041 x 0.975
P(PT∩ NI) = 0.039975
P(PT) = P(PT∩ I)+P(PT∩ NI)
P(PT)= 0.0226 + 0.039975
P(PT) = 0.062575
P(I/PT) = P(PT∩I)/P(PT)

So, the first thing we need to know is what is what.
So, A natural number is a whole number
A whole number is an integer
and An integer is a rational number.
Now, since there is a terminating decimal (a decimal that does not go on forever) we know it is a rational number.
Since there is a decimal, it cannot be an integer, therefore
It is a rational number
Answer:

Step-by-step explanation:
Given
+ x
Multiply x by
to create a common denominator
=
+ x × 
=
+ 
= 