Hello tutors, can I please get you assistance with the following ? Thank You so much

The random variables X and Y are continuous random variables that vary according to the following joint density function:

(,) = 15⁽³⁺⁵⁾ , 0 , 0 How could you show that for these random variables,()=()()starting with the definition of E(XY). (Note: XY is the product of X and Y).

*please display the steps, what is on the left hand side of the equal signs, the final answer*