Răspuns :
a + b + c= 130
b=3a
c=3b=3a x 3=9a
a + 3a + 9a = 130
13a=130
a= 130 :13
a = 10
b= 10x3=30
c= 30x3=90
b=3a
c=3b=3a x 3=9a
a + 3a + 9a = 130
13a=130
a= 130 :13
a = 10
b= 10x3=30
c= 30x3=90