Metoda algebrica:
a + b = 85
a = b : 4 ==> b = 4×a
a + 4×a = 85
5×a = 85
a = 85 : 5
a = 17
b = 4×17 = 68
Verificare:
17 + 68 = 85
Metoda grafica:
a |--------|
b |--------|--------|--------|--------|
Avem 5 segmente egale = 85
85 : 5 = 17 (un segment egal)
a = 17
b = 4×17 = 68