Answer:
y = 3
Explanation:
Pythag theorem : ( only applies to RIGHT triangles)
Hypotenuse ^2 = leg1 ^2 + leg 2^2
(7y-1)^2 = (5y-3)^2 + (5y+1)^2
49 y^2 - 14y +1 = 25y^2 -30 y + 9 + 25y^2 + 10y + 1
-y^2 + 6y -9 = 0
or y^2 -6y + 9 = 0 solve by factoring or using Quadratic Formula
( y -3)(y-3) = 0 shows y = 3