Answer:

Step-by-step explanation:
see the attached figure with letters to better understand the problem
we know that
In the right triangle ABD

In the right triangle BCD

remember that
m< BAD=m<CBD
therefore

equate the equations



Answer:
The score of the dropped grade is 6
Step-by-step explanation:
To find the average of a set of numbers you need to add all the numbers and divide by how many numbers there are. The problem wants you to solve it in reverse. Let put this into an algebraic equation with a, b, c, d, and e being the variables of the test scores
(a+b+c+d+e)/5=10
Then we can multiply both sides by 5 and get
a+b+c+d+e=50
Lets assume that c is the lowest test score. To calculate the average of that we get
a+b+d+e/4=11
Doing the same thing, we know that a+b+d+e=44
Now compare the two:
a+b+c+d+e=50
a+b+d+e=44
We can now know that c=50-44=6
So, 6 is the score of the dropped quiz. Hope that helped!
It is eight. There is no way it's wrong I doubled checked.
89.95 x 0.05 (5%)
=4.4975
The final cost of the DVD player is 89.95-4.4975
=85.4525
≈ $85.45