I believe it’s 90 I’m not sure but
Number 1 and number 3 are the same because if you are purchasing three tires that is 75% off the tires you need and one of them you get free. the free one becomes the overall discount of 25% off. number 3 is the same, the one quarter represents 25% off of the purchase.
The mean is not the same thing as median
mean=78+81+85+87=331
mean=331/4=82.75
median is the middle number, but you have a par set of numbers, so your median will be the middle numbers 78,81,85,87 , which are 81+85=166, 166/2=83
83 is your median
Answer: see proof below
<u>Step-by-step explanation:</u>

Use the following Identities:
sec Ф = 1/cos Ф
cos² Ф + sin² Ф = 1
<u>Proof LHS → RHS</u>






<h3>
Answer: w^2 + 3w - 10</h3>
===============================================
Work Shown:
Let x = w-2
This will allow us to replace the (w-2) with x to get...
(w-2)(w+5)
x(w+5)
x*w + x*5 ... distribute
w(x) + 5(x)
Now replace x with w-2 and distribute again
w(x) + 5(x)
w(w-2) + 5(w-2)
w*w + w*(-2) + 5*w + 5*(-2)
w^2 - 2w + 5w - 10
w^2 + 3w - 10