Given a=15,b=9a=15, b=9a=15,b=9, which pair (x,y)(x, y)(x,y) satisfies 15x+9y=gcd(15,9)15x + 9y = \text{gcd}(15, 9)15x+9y=gcd(15,9)?
(1,−1)(1, -1)(1,−1)
(2,−3)(2, -3)(2,−3)
(1,−2)(1, -2)(1,−2)
(0,1)(0, 1)(0,1)