А) 30142 + z = 49*876
30142 + z = 42924
z = 42924 - 30142
z = 12782
б) 51815:(p-975) = 1205
p-975 = 51815:1205
p-975 = 43
p = 43 + 975
p = 1018
в) 13x + 15x - 24 = 60
28x = 60 + 24
28x = 84
x = 84:28
x = 3
г) 18y - 7y - 10 = 12
11y = 10 + 12
11y = 22
y = 22:11
y = 2