X/y - y/x = 15/4
4(x/y)^2 - 15(x/y) - 4 = 0
(4(x/y) + 1)((x/y) - 4) = 0
a) x/y = 4, x = 4y
x^2 + y^2 = 153
16y^2 + y^2 = 153
17y^2 = 153
y^2 = 9
y = 3, x = 12
y =-3, x =-12
б) x/y = -1/4, y = -4x
x^2 + y^2 = 153
x^2 + 16x^2 = 153
x^2 = 9
x = 3, y = -12
x =-3, y = 12
x1 = 12, y1 = 3
x2 =-12, y2 =-3
x3 = 3, y2 =-12
x4 =-3, y2 = 12