how to solve this??

Question

13y=10
x+Y+Z=39
16x=13z

Answer 1

from the first: y = 10/13

from the last: z = 16/13x

into the second:
x + 10/13 + 16/13x = 39
times 13
13x + 10 + 16x = 507
29x = 497
x = 497/29

now I can find z = (16/13(497/29) = 7952/377

x = 497/13 , y = 10/13 , z = 7952/377

weird!