00:01
We're given the cost expression is 60x plus 300 where x represents the number of items, and the revenue is represented by 100x minus 0 .5x squared.
00:14
We know the definition of profit is the revenue minus the cost, and we want to write an expression for this situation to represent the profit.
00:37
So we're going to use these two expressions to represent profit.
00:42
So we need to do the revenue minus the cost.
00:50
So our revenue was the 100x minus 0 .5x squared.
00:58
And our cost is 60x plus 300.
01:04
So we simplify that.
01:08
And let's go ahead and put the, exponents in descending order.
01:13
So let's put this negative 0 .5 x squared first.
01:24
And then we have this 100x minus 60x that gives us 40x and then we have this minus this positive 300.
01:38
So that would be minus 300 and that would be our expression that represents the profit.
01:47
Let's do this.
01:50
Let's go ahead and put that zero there, told that place value.
01:53
So we've answered half the question.
01:56
The b part says find two values for x when the profit is $300...