00:01
Hi there, so for this problem, the available fencing for this that corresponds to the perimeter is equal to 500.
00:12
Now, we're going to label the horizontal side of this as x and the vertical sides as y.
00:21
Then we know that the one in the middle also has a dimension x, okay? now, then we are given information about the cost for each side.
00:40
So with that we can write the cost function for this.
00:44
Okay, so the left and right sides cost $2 per foot.
00:50
So we need to multiply two times, and we have two sides, there are y.
00:56
So that will be then two times y in here.
00:59
This plus and the back side costs 5 per food.
01:05
So x, we will have 5 times x.
01:11
And the one in the middle, the femmes in the middle, costs 1 per food.
01:18
So that will be just simply x.
01:21
So the cost function becomes 4 times 1 plus 6 times x.
01:27
Now, let's write the expression for the perimeter, the perimeter is just a sum of all of the sides for this.
01:33
So we'll have 2 times y plus 2 times x.
01:38
Simplifying this, we can divide everything by 2.
01:42
So we'll have 250 is equal to x plus y.
01:46
Now in here we can solve for y, so that will be 250 minus x.
01:51
And then we can substitute that into the cost function...