Notam cu S- suma initiala
b-pretul bicicletei
c-pretul chitarei
S=b+c+400
1/3dinS=b⇒b=S/3
Rest=2/3dinS
c=1/3dinRest=[tex] \frac{1}{3}* \frac{2}{3}*S= \frac{2}{9} *S [/tex]
S=400+S/3+2S/9
Se aduce la acelasi numitor⇒3600+3S+2S=9S
4S=3600
S=900
b=900/3=300
c=2/9*900=200