Answer:
Profit 6,130
Explanation:
MC = 30X + 4
when X=5
Cost to produce 5 units:
We will need to calcualte the MC for 1, 2 , 3, 4 and 5 units and then add them together
MC = 30(5) + 4 = 150 + 4 = 154
MC = 30(4) + 4 = 150 + 4 = 124
MC = 30(3) + 4 = 150 + 4 = 94
MC = 30(2) + 4 = 150 + 4 = 64
MC = 30(1) + 4 = 150 + 4 = 34
Total 470
Giving this, now anther way, more easy would be to use the Gauss method to a summatory:

S to 5 from 1 of (30x+4) =

S = 470
Now we can continue:
Total Marginal cost 470 + Fixed Cost: 900 = 1370
MR = 1500 revenue for adding 1 unit
1500 x 5 = 7500 total revenue
total revenue - total cost = profit
7500 - 1370 = 6,130