Question

Hallar la media aritmética de a ; -b ; -c .Sabiendo que : (a+2b)/5 = (c-3b)/2 = (a+c)/3 = 2 .

a)16 b)14 c)12 d)18

Answer 1

A + 2b = 10
c - 3b = 4
a + c = 6

a + c - (c - 3b) = 6 - 4
a + 3b = 2
a = 2 - 3b
a = 10 - 2b

2 - 3b = 10 - 2b
2 - 10 = 3b - 2b
-8 = b
a = 2 - 3b = 2 - 3(-8) = 26
c = 6 - a = 6 - 26 = - 20

Hallar la media aritmética de a ; -b ; -c
(a - b - c)/3 = (26 + 8 + 20)/3 = 54/3 = 18