This is a difference of perfect squares which is of the form:
(a^2-b^2)
And which always factors to:
(a-b)(a+b)
In this case:
(5x-8)(5x+8)
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>
To solve this, you would divide the miles by the number of hours, 21 / 4
21 divided by 4 equals 5.25
Yes the ratio would change because it needs 3 times more than the original amount so you would multiply it by 3