The sum of two numbers is 4. Their difference is 12. What are the two numbers? Write a system of equations for this situation and find its solution. What is 15 more than the smaller of these two numbers?
Let the larger number be L, and the smaller, S
Then we have: L + S = 4 ----- eq (i)
Also, L - S = 12 ------------ eq (ii)
2L = 16 ----- Adding eqs (ii) & (i)
L, or larger number = 
Do you think you can find the smaller number? If so, just add 15 to it to get the answer to part 2.
It's that simple....nothing COMPLEX!!