1. 30
2. 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74; 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 254, 256, 258, 260, 262, 264
3. 640; 1280
|y| - 2 = 1
|y| = 1 + 2
|y| = 3
y = 3
|5y| - 4 = 6
|5y| = 10
|y| = 10\5
y = 2
1+5, 2+5, 3+5, 4+5, 5+5;
10-5, 9-5, 8-5, 7-5, 6-5, 5-5.
Надеюсь что помогла!!!