Solution
For this case we can use the following operation to solve the problem
C= 24 + 0.70 x (Represent the cost function with x the number of DVD duplicated)
R= 150 represent the revenue
Then we can do this:
R= C
150= 24 +0.7x
And solving for x we got:
0.7x= 126
x = 126/0.7= 180
and then the solution for this case would be 180 units for the brak even point