Yes, that is correct. 10 to the 5th is 100,000. so that divided by 100 = 1000. Hope it helps!
It is 70% Because:
250/100 + 175/x
Proportions
First lets get the formula for a triangular prism

First lets plug in our numbers

It really doesnt matter how you multiply everything, but you end up with 119cubic feet.
So first off, remember the formula for the area of a rectangle. it's length time width right? or, you could think that A= 2 things multiplied together. how can we simplify x^2 - x -72 to equal two things multiplied together? well, we can factor it! We know that one of the factors is x+8 right? so what's the other factor? it would be x-9. so, we know width is x-9. I'm not sure if you need an actual value for width. if so, I could probably go further.
Y - 2 = -3/4 (x - 6)
y = -3/4 (x - 6) + 2
When, x = -2,
y = -3/4 (-2 - 6) + 2 = -3/4 (-8) + 2 = 6 + 2 = 8
One point is (-2, 8)
When, x = 2,
y = -3/4 (2 - 6) + 2 = -3/4 (-4) + 2 = 3 + 2 = 5
Another point is (2, 5)