Which numbers when multiplied give you 16 and when added give you 8. *

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

When you answer this can you explain

It says factor each expression completely 8y+48