12.
(a + b + c) ÷ 3 = 39
a + b + c = 39 × 3
a + b + c = 117
Suma = 117
13.
(a + b + c) ÷ 3 = 28
a + b + c = 28 × 3
a + b + c = 84
(a + b) ÷ 2 = 33
a + b = 2 × 33
a + b = 66
c = 84 - 66
c = 18
14.
a = 3b
(a + b) ÷ 2 = 12
a + b = 12 × 2
a + b = 24
3b + b = 24
4b = 24
b = 24 ÷ 4
b = 6
a = 3 × 6
a = 18
15.
a + b + c + d = 70
(a + b + c + d) ÷ 4 = 70 ÷ 4
(a + b + c + d) ÷ 4 = 17,5
Media = 17,5
16.
(a + b + c + d) ÷ 4 = 237
a + b + c + d = 4 × 237
a + b + c + d = 948
- Lumberjack25
