2 Equations - Don't know where to start

Ok got 2 algbaric equations.

Can someone help me here..... really really confused where to start.

Here they are...

0.8v + 0.54y -1.6z > 0

where

v + y + z = 1 (v,y or z cannot be <0)

Help much appreciated

Need value(s) for z only really, but if you can get the value(s) of y and v that would be nice too:)

I did post this in the advanced section but looking at some others this looks basic in comparison so thoguht I might get a quicker response here!

Many Thanks for your help :)