Metoda grafică :
p |--------|-9-| } 39 kg
l |--------|
39 - 9 = 30 kg ( 2 segmente egale )
30 : 2 = 15 kg ( 1 segment )
p = 15 + 9
p = 24 kg
l = 15 kg
__________________
Metoda algebrică :
p + l = 39 kg
p = l + 9
l + 9 + l = 39 kg
2l = 39 - 9
2l = 30 kg
l = 30 : 2
l = 15 kg
p = 15 + 9
p = 24 kg