1) c²+8-9c²-10 = -8c²-2
2)-a²+a-6a-4a² = -5a²-5a
3)-2m+4m²-m³+m+m² = -m³+5m²-m
4)3x²y-3x²y²-3x²y²+x²y = -6x²y²+4x²y
1) c²+8-9c²-10 = -8c²-2
2)-a²+a-6a-4a² = -5a²-5a
3)-2m+4m²-m³+m+m² = -m³+5m²-m
4)3x²y-3x²y²-3x²y²+x²y = -6x²y²+4x²y