00:01
Here we are given that an apple grower finds that if he plants 80 trees per acre, each tree will yield 26 bushers of fruit.
00:09
Now, we know that yield, we'll call it y, is equal to the number of trees multiplied by the yield per tree.
00:30
And we're also given that he estimates that for each additional tree planted per acre, the yield of each tree will decrease by four bushels.
00:39
Now we're going to say let x be the number of additional trees and therefore our yield will be equal to.
00:56
Now for the 80 plus an additional x we have a yield of 26 bushels minus four bushels from every tree for each added tree.
01:15
So our expression would be y is equal to 80 plus x by 26 minus 4x.
01:26
Now expanding this, we have y is equal to 80 by 26.
01:31
We get 2 ,080.
01:34
80 by minus 4x.
01:36
We get minus 320x.
01:40
X by 26, we get plus 26 x, then minus 4x squared.
01:48
Simplifying this, we have 2080 minus 294x minus 4x squared...