1) (400-20)2 = 4002 - 202 = 800 - 40 = 7602) (80-1)5 = 805 - 15 = 400 - 5 = 3953) (25-9)4 = 254 - 94 = 100 - 36 = 644) (20-1)7 = 207 - 17 = 140 - 7 = 133
1) (400-20)2 = 4002 - 202 = 800 - 40 = 760
2) (80-1)5 = 805 - 15 = 400 - 5 = 395
3) (25-9)4 = 254 - 94 = 100 - 36 = 64
4) (20-1)7 = 207 - 17 = 140 - 7 = 133