Question 962344
Solve for x,y by substitution 
8x-y=13
 y=-8x+1
-------
Substitute for "y" and solve for "x"::
8x - (-8x+1) = 13
---
8x+8x-1 = 13
16x = 14
x = 7/8
--------------
cheers,
Stan H.
-------------