Question

Can anyone prove this?
If x > y and z > w, then x+z > y+w

Answer 1

x>y (1)
z>w (2)
------ +
x+z>y+w

I'm not sure how rigorous of a proof you want, but that seems legit to me

Answer 2

thank but not exactly what i was looking for. I need something...more...

Answer 3

Another way you can look at it would be
since x > y
x + z > y or any variable you put in place for z will always be greater than y
as well as z > w
x + z > w or any variable you put in place for x will always be greater than y
so this just states
x + z > y + w
since both values are greater.
I'm not sure how much that helps, but it is a different way to look at it.

Answer 4

thanks! That helped a lot!