Answer:
The numbers are:
5, 12 and 4
Step-by-step explanation:
a + b + c = 21 Eq. 1
b = 2a +2 Eq. 2
b = 3c Eq. 3
From Eq. 2:
b - 2 = 2a
(b-2)/2 = a Eq. 4
From Eq. 3:
c = b/3 Eq. 5
Replacing Eq. 4 and Eq. 5 in Eq. 1:
(b-2)/2 + b + b/3 = 21
3(b-2)/6 + 6b/6 + 2b/6 = 126/6
3(b-2) + 6b + 2b = 126
(3*b + 3*-2) + 8b = 126
3b - 6 + 8b = 126
11b = 126 + 6
11b = 132
b = 132/11
b = 12
from Eq. 4
(b-2)/2 = a
(12-2)/2 = a
10/2 = a
a = 5
from Eq. 5
c = b/3
c = 12/3
c = 4
Check:
from Eq. 1
a + b + c = 21
5 + 12 + 4 = 21
