Answer:
a=21
b=25/2
c=77/2
Step-by-step explanation:
from eq 1
a+4=2b => a=2b-4
substituting value of a in eq 2
c-5=a+b => c-5=2b-4+b => c =3b+1
now, substituting value of a and c in eq 3
a+b+c=72 => 2b-4+b+3b+1 =72 => 6b-3=72 => b= 75/6 => b=25/2
substituting value of b in :
c=3b+1 ( you will get c )
then substitute value of b in :
a=2b-4 ( to get a)
