5 (1+м) (1-м) - (2 - м) ^2 - 8 (1 - м) ^2

упростить выражение

5 (1+m) (1-m) - (2-m) ²-8 (1-m) ²=

1) 5 (1+m) (1-m) = (5+5m) (1-m) = 5-5m+5m-5m²=5-5m²

2) (2-m) ² = (2-m) (2-m) = 4-2m-2m+m²=4-4m+m²

3) 8 (1-m) ²=8 (1-m) (1-m) = (8-8m) (1-m) = 8-8m-8m+8m²=8-16m+8m²

= (5-5m²) - (4-4m+m²) - (8-16m+8m²) = 5-5m²-4+4m-m²-8+16m-8m²=

=-14m²+20m-7