5^(2x-y)=5^(-1) -> 2x-y=-1, y=2x+1
5^(2x) + 5^(2x+1) = 6sqrt(5)
5^(2x)+5*5^(2x)=6*5^(1/5)
5^(2x)=5^(1/2)
2x=1/2
x=1/4
y = 2x + 1 = 1/2 + 1 = 3/2
xy = 3/8 = 0.375
5^(2x-y)=5^(-1) -> 2x-y=-1, y=2x+1
5^(2x) + 5^(2x+1) = 6sqrt(5)
5^(2x)+5*5^(2x)=6*5^(1/5)
5^(2x)=5^(1/2)
2x=1/2
x=1/4
y = 2x + 1 = 1/2 + 1 = 3/2
xy = 3/8 = 0.375