CPhill

I believe you might want this??

347.12 / 4

Think of it this way......if I mutiply 86.78 by 4, I get something that will give me 86.78 back when I divide it by 4. That "thing" is 347.12.

We can't give a specific answer...for instance, if y = -6, x = 0. But if y = 0 , x =4.

All we can do is to specify x in terms of y.

Add 2y to the equation and then divide by 3

3x = 12 + 2y

x = (12 + 2y) / 3

And that's x in terms of y

A = (1/2) (base) x (height)

To find the percent decrease we have......... (old price - new price) / (old price)  =

(70 - 56) / (70)   = .20  = 20% decrease

We'd have to know what c and d are to answer that.......if you just wanted to factor it, we have.....

8c(1 - 3d)

BTW, zegroes, I gave you a thumbs-up for creativity!!!

While zegroes is technically correct, let's see if we can give a more "complete" answer.......

105 / 60 = 1.75 hrs.

Nope.......the distance will change, but so will the angle of elevation.........also, if the tangent only "worked" at certain distances, it would be largely useless.

Think of it this way......suppose we could tie a string to the top of the tree and anchor the other end of it in the ground some distance from the tree. Now, move the anchor point closer to the tree. The angle of elevation is different, but the height of the tree is the same. The angle of elevation would decrease if we moved the anchor point away from the tree, but again, the tree's height would be the same.

Here you go........

For those interested, here's a proof by Euclid: