1) 89 - 25
89 - 25 = 64
: 8
64 : 8 = 8
* 30
8 * 30 = 240
+ 60
240 + 60 = 300
2) 300 * 2
300 * 2 = 600
- 250
600 - 250 = 350
: 7
350 : 7 = 50
- 50
50 - 50 = 0
3) 31 + 169
31 + 169 = 200
* 7
200 * 7 = 1400
- 400
1400 - 400 = 1000
: 2
1000 : 2 = 500
4) 36 : 12
36 : 12 = 3
* 50
3 * 50 = 150
+ 350
150 + 350 = 500
- 100
500 - 100 = 400
Ответ: 1) 300, 2) 0, 3) 500, 4) 400