4003243 4003243 21-01-2021 Mathematics contestada Solve the system by substitution. 1. 5x + y = -17 -3x - 3y = 3 Solve the systems by elimination. 2. x - y = 11 2x + y = 19 3. -7x + y = -19 -2x + 3y = -19 4. 4x + 6y = 10 6x = 9y - 3