00:01
So for this equation, we want to start with finding nine gallons, what the cost is.
00:05
What we'll do is we'll put a nine in here for the x and multiplying that.
00:10
So 350 times nine, and then add that seven, and we get 38 .5.
00:17
So 38 .5.
00:20
And also we want to find out four gallons.
00:26
So let's do y equals 3 .50.
00:32
Times four plus the seven.
00:36
So let's go ahead and do 350 times four, and then let's add that seven on, and we get 21.
00:45
21, so y equals 21.
00:48
So that's part a.
00:49
We have two answers here.
00:51
Why equals that? why equals that? so that was part a.
00:54
Let's do part b.
00:56
Part b is basically looking at if we paid $35, what was the number of gallon? so let's put 35 into the y this time.
01:08
And let's do 350x plus 7.
01:12
And let's solve for x here.
01:14
So subtract 7 off both sides and then divide by 350.
01:19
So 28 divided by 350 is 8...