2.50x + 1.75y < or = to 15

y < or = 1.43x + 8.57

y = 8.57

I'm having a brain cramp and trying to find x has been a lost time tonight. Plese help what is x

The second inequality can be derived from the first one.
The third statement, y=8.57, does not follow from the second. Is it independent information that you were given?
If y=8.57, then
8.57 <or= 1.43 x + 8.57
0 <or= 1.43 x
x >or= 0