Răspuns :
A+b= 100
A= b:4=> b= 4xa
A+ 4xa= 100
5xa = 100
A= 100:5
A= 20
B= 20x4
B= 80
V: 20+ 80= 100
A= b:4=> b= 4xa
A+ 4xa= 100
5xa = 100
A= 100:5
A= 20
B= 20x4
B= 80
V: 20+ 80= 100
a+b=100
a=b/4
b/4+b=100
b+4b=400
5b=400
b=80
a+b=100 => a+80=100
a=100-80
a=20