x-portocale
y-mere
x= 2786 kg
y= 7890 kg
z- noua cantitate adusa
x+z= 15360 kg
y+z=?
------------------------------------------------
Din relatiile
x+z= 15360 kg
x= 2786 kg
Putem afla z
x+z= 15360 kg
2786 kg+ z= 15360 kg
z= (15360- 2786) kg
z= 12574 kg
Din relatiile
y= 7890 kg
y+z=?
Inlocuim fiecare termen
(7890+12574) kg= 20464kg MERE TOTAL