Answer: The level of production is 4 units and the corresponding price that maximize the profits is $121.
Step-by-step explanation:
Since we have given that
the demand for steel would be


Total cost of producing x units of steel would be

Profit = R(x)-C(x)
So, it becomes,

First we derivative w.r.t to x we get that

Now, we will find the critical points,

So, now second derivative w.r.t. x.
We get that

So, there will be maximum profit at 4 units of level of production and the corresponding price that maximize the profit would be

Hence, the level of production is 4 units and the corresponding price that maximize the profits is $121.