**1. The problem statement, all variables and given/known data**
In drilling an oil well, the total cost, C, consists of fixed costs (independent of the depth of the well) and marginal costs, which depend on depth; drilling becomes more expensive, per meter, deeper into the earth. Suppose the fixed costs are 1,000,000 riyals (the riyal is the unit of currency of Saudi Arabia), and the marginal costs are C'(x) = 4000 + 10x riyals/meter, where x is the depth in meters. Find the total cost of drilling a well x meters deep.

**2. Relevant equations**
I'm using I'll use a definite integral.

**3. The attempt at a solution**
Here's what I tried.