00:02
All right, so here we have farmer brown planting corn and wheat.
00:06
He has a total of 1 ,190 acres on which to plant his crops.
00:11
The cost of planting corn is $270 an acre.
00:16
The cost of planting and harvesting his wheat is $140 an acre.
00:20
And we want to know how much of each, well in particular, how much corn he plants, if the total cost is $249 ,800.
00:31
So we're going to let c equal the number of acres of corn and we're going to let w equal the acres of wheat.
00:52
And we know that $270 times the cost of corn plus $140 times the cost of wheat is equal to $249 ,800.
01:11
So that's total cost plus total cost.
01:14
Total cost of corn, total cost of wheat equals total cost of both crops.
01:24
And then we also know that the number of acres of corn plus the number of acres of wheat has to equal 1 ,190.
01:33
So we have two equations and two variables and there are a couple of ways that we can solve this.
01:40
But the easiest it looks like to me would be substitution.
01:44
So i'm going to take this second equation, the c plus w equals 1 ,190, and i'm going to solve that for either one of the variables.
01:53
It doesn't matter since i'm asked to solve for corn.
01:57
I'm going to go ahead and just solve this one for corn.
02:00
So the number of acres of corn is going to be 1 ,190 minus w...