1) x + 60 = 2000 : 8
x + 60 = 250
x = 250 - 60
x = 190
2) 720 : x = 20
x = 720 : 20
x = 36
3) 350 : x = 50
x = 350 : 50
x = 7
4) x · 30 = 150
x = 150 : 30
x = 5
Ответ: x = 190; x = 36; x = 7; x = 5.