ornthen ornthen 22-12-2020 Mathematics contestada Select all the systems of equations that have exactly one solution. y = 3x + 1, y = -3x + 7 y = 3x + 1, y = x + 1 y = 3x + 1, y = 3x + 7 x + y = 10, 2x + 2y = 20x+ y = 10, x + y = 12