1) 450 - 80 / 2 - 230= 180
80 / 2 = 40
450 - 40 = 410
410 - 230 = 180
2) 48 х 2 + 900 - 90 = 906
48 х 2 = 96
96 + 900 = 996
996 - 90 = 906
3) 84 / 14 х 100 - 560 = 40
84 / 14 = 6
6 х 100 = 600
600 - 560 = 40
4) 750 - 16 х 5 + 3 х 100 = 375380
16 х 5 = 80
3 х 100 = 300
80 + 300 = 380
750 - 380 = 370