Răspuns:
Explicație pas cu pas:
1. n = 5a
m = 5b
p = 5c
a+b+c / n+m+p = a+b+c / 5a+5b+5c = a+b+c / 5(a+b+c) = 1/5
2. 15 b = 12 a
24 c = 18 a
a + 12a/15 + 18a/24 = 51
a + 4a/5 + 3a/4 = 51
(20a + 16a + 15a) / 20 = 51
51a = 51 x 20
a = 20
b = 4a/5 => b = 16
c = 3a/4 => c = 15
3. a = 2x
b = 2y
c = 2z
2x + 2y + 2z = 2(x+y+z) = 2 x 4,5 = 9
