jillianrobbins96 jillianrobbins96 14-11-2022 Mathematics contestada Simplify: -6m² n² + 3mn + 4mn + 13m² n² +9 O 14m² n² +9 O 7m²n + 7m² n² +9 O19m² n² + 7mn +9 O 7m² n² + 7mn +9