Answer:
a) 1680
<em>The number of ways to listen to four CDs from a selection of 8 CDs = 1680</em>
Step-by-step explanation:
<u><em>Explanation:-</em></u>
Given data the number of CD' s n = 8
<em>We have to selected '4' CD' s from total '8' CD's</em>
<em>By using permutations </em>
<em>The number of ways to listen to four CDs from a selection of 8 CDs.</em>
<em> = </em>
<em> </em>
<em> we know that </em>


<em>The number of ways to listen to four CDs from a selection of 8 CDs = 1680</em>
On the x column, you would write 1, 2, 3, 4, and so on. Then, in the y box, you plug in that number into the equation. Write your answer in the y column.
For example, if x = 1, then 1^2 + 2 - 8 = - 5.
If x = 1, y= -5
Answer:
b =15
Step-by-step explanation:
We can use Pythagoras theorem to find b:


64 +
= 289
64 + 225 = 289
64 +
= 289
b = 15
hope this helps :) and sorry if not right