3х+х+3=27
4х=27-3
4х=24
х=6
проверка:6*3=18,6+3
9+18=27
28 + y = 33
y = 33 - 28
y = 5
28 + 5 = 33
33=33
12 + x = 17
x = 17 - 12
x = 5
12 +5 = 17
17=17
24 + x = 29
x = 29 - 24
x = 5
24 + 5 = 29
29=29
30 + x = 35
x = 35 - 30
x = 5
30 + 5 = 35
35 = 35
16 + y = 21
y = 21 - 16
y = 5
16 + y = 21
21=21
1) 960 / 8 = 120ч. ракета пройдет 960км со скоростью 8км/ч
2) 120 * 60 = 7200 минут