This is a simultaneous question that can be solved with elimination.
6x - 5y = 0 ——(1)
x - 5y = -25 ——(2)
(1) - (2):
6x - 5y - (x - 5y) = 0 - (-25)
6x - 5y - x + 5y = 0 + 25
5x = 25
x = 5
Sub x = 5 into (2):
5 - 5y = -25
-5y = -30
y = 6
Hope this helps