Answer:
x=2, y=1
x=-2, y = -1
Step-by-step explanation:
x - 2y = 0
x = 2y
x² - y² = 3
(2y)² - y² = 3
3y² = 3
y² = 1
y = 1 or y = - 1
x = 2 or x = -2
