Răspuns :
a+b+c=470
b=3 x a
b=20+c
c=b-20= 3 x a -20
a+3 x a+3 x a - 20 =470
7 x a = 470+20
7 x a = 490
a= 490:7
a=70
b=70 x 3 =210
c= 210-20 =190
b=3 x a
b=20+c
c=b-20= 3 x a -20
a+3 x a+3 x a - 20 =470
7 x a = 470+20
7 x a = 490
a= 490:7
a=70
b=70 x 3 =210
c= 210-20 =190