Answer:
8190 ways
Step-by-step explanation:
Given


Selection


Required
Number of ways of selection
4 students can be selected from 15 students in:

Similarly.
5 teachers can be selected from 6 teachers in:

So, the required number of selection is:

Apply combination formula:







Answer:
I think they are independent
Step-by-step explanation:
We know that coordinates are labeled (x,y)
The formula to find slope is (Y2-Y1)/(X2-X1)
So (2- (-7))/(-6-(-6) undefined because the denominator is zero. The line looks like a vertical line at x=-6
So you can use
$21.95 + $.19x = $18.95 + $.21x