Which equation results from adding the equations in this system? x + 6 y = 9. Negative x + 2 y = negative 15. 8 y = negative 6 8 y = 6 4 y = 24 4 y = negative 6Which equation results from adding the equations in this system? x + 6 y = 9. Negative x + 2 y = negative 15. 8 y = negative 6 8 y = 6 4 y = 24 4 y = negative 6