Let B be the event that Andrea passes her test, and let A be the event
<span>that she studies. We are given that P(A and B) = 17/20, and that P(A) = 15/16. </span>
<span>Now the probability that Andrea passes her test given that she has studied </span>
<span>is represented by P(BlA). The formula your teacher gave you can be written as </span>
<span>P(BlA) = P(A and B) / P(A). </span>
<span>So P(BlA) = P(A and B) / P(A) = (17/20) / (15/16) = (17/20)*(16/15) = 68/75.</span>
An=a1+d(n-1)
an=nth term
a1=first term, when n=1
d=common differnce=amount each term increases by
n=which one
so
when n=1, an=40
so a1=40
it seems to increas by 7 each time
an=40+7(n-1)
explicit formula is expanded
an=40+7n-7
an=33+7n is the formula
the domain is natural numbers because you can't have the -3rd term or the 0th term or the 3.24th term
domain is natural numbers
the formula is

or
Hi Kristian
a - 3b = 22
a = b - 2
We need to solve a = b -2 for a
First, we need to substitute b - 2 for a in a - 3b = 22
a - 3b = 22
b - 2 - 3b = 22
-2b - 2 = 22
-2b = 22 + 2
-2b = 24
b = 24/-2
b = -12
Now substitute -12 for b in a = b - 2
a = b -2
a= -12 - 2
a= -14
Thus, the solution is a = -14 and b = -12
The correct option is the last one (-14,-12)
If you have questions about my answer, please let me know.
Good luck!