Answer:

Step-by-step explanation:
We want to find an expression that has a value of

First option:

Second option:

Correct option
Third option

Fourth option:

I think the answer is 3, because D(12;-4) and D' is (36;-12). Then 36/12=3, -12/-4=3
(I hope it's true)!!! :)
Profit will be achieved when the money earned is greater than the money spent so,
336 + (n*12) = n*28 any subsequent units sold would result in profit
336 = 28n - 12n
336 = 16n
=> n = 336/16 = 21
21 units must be sold to draw even any more would result in profit