1. C; B; B
2. 90+76=166
90-76=24
56+45=101
56-45=11
9+2=11
9-2=6
3. 50+19=69 pere
69×3=207 căpșuni
4.997665221
5.10000000009, 1000000, 678954, 6789, 500, 55, 23
6.1 rest 2
7.999976-500000=499972
999976:500000=1999952
999976×50000=499998000000
8.499998000000+4999972 =499,989,999,952