Răspuns :
a : b = 20 : 4
a : b = 5
a - b = 36
a = 5 × b
5 × b - b = 36
4 × b = 36
b = 36 : 4
b = 9
a = 5 × 9
a = 45
a : b = 5
a - b = 36
a = 5 × b
5 × b - b = 36
4 × b = 36
b = 36 : 4
b = 9
a = 5 × 9
a = 45
A-b=36
a:b=20:4=5
a |......|.....|.....|.....|.....| } 36
b |......| }
36:4=9(b)
9×5=45(a)
Proba: 45-9=36