(85 - a) x 2 = 10
85 - a = 10 : 2
85 - a = 5
a = 85 - 5
a = 80
(45 : b) : 3 = 3
45 : b = 3 x 3
45 : b = 9
b = 45 : 9
b = 5
(c : 7) : 8 = 56
c : 7 = 56 x 8
c : 7 = 448
c = 448 x 7
c = 3136
a + b + c = 80 + 5 + 3136
a + b + c = 85 + 3136
a + b + c = 3221