Expectation and Variance of Industrial Operations

Please provide a solution for the following problem:

For the daily output of an industrial operation, let Y1 denote the amount of sales and Y2, the costs, in thousands of dollars. Assume that the density functions for Y1 and Y2 are given by (see attachment).
The daily profit is given by U =Y1 – Y2.

a. Find E(U).
b. Assuming that Y1 and Y2 are independent, find V(U).

Thanks for your assistance.

Please see the attached document.

Please provide a solution for the following problem:

For the daily output of an industrial …

This solution shows step-by-step calculations to determine E(U) and using Y1 and Y2 it finds V(U).