00:01
All right, we're given cost functions 30x plus 1 ,200, and a revenue function, r of x equals 38x.
00:10
X is the number of units produced or sold.
00:12
We want to determine marginal profit.
00:14
Well, first off, let's figure out what profit is.
00:16
Profit is going to be what you take in minus your expenses.
00:21
So r, revenue minus cost c.
00:23
That's 38x minus the quantity 30x plus 1 ,200.
00:29
Make sure that's all in parentheses.
00:31
So you get 8x minus 1 ,200...