Step 1. Simplify
7x^2 - 8x - 4 - 2x^2 + 3x + 5 + 5x^2 - 10x - 8
Step 2. Collect like terms
(7x^2 - 2x^2 + 5x^2) + (-8x + 3x - 10x) + (-4 + 5 - 8)
Step 3. Simplify
10x^2 - 15x - 7
For this case we have a function of the form:

Where,
A: initial amount
b: decrease rate
x: time in days
Substituting values we have:

Therefore, the graph of the function is a decreasing exponential function in the first quadrant and that has an initial value of 40.
Answer:
graph of exponential function going from left to right in quadrant 1 through the point 0, 40 and approaching the x axis
Step-by-step explanation:
Put the interior angle equal to 180.
It would look something like this:
x+45=180
-45 -45
180-45= 135 so the exterior angle would be 135!