Question

Doua kilograme de rosii si 3 kg de mere costa 17 lei. Trei kg de rosii si 5 kg de mere costa 27 lei. Cat costa 1 kg mere si cat costa 1 kg rosii

Answer 1

2r + 3m = 17      | * 3
3r + 5m = 27      | * 2  
6r + 9m = 51
6r + 10m = 54
le scadem
  /    m  = 3 lei/kg merele
2r + 3 * 3 = 17
2r = 17 - 9
r = 8 : 2
r = 4 lei/kg rosiile

Answer 2

a=kg rosi 
b=kg mere
2a+3b=17 /x(-3)
3a+5b=27  sistem /(2)
-6a-9b=-51 
6a+10b=54 le adunam =>b=3lei =>2a+9=17=>2a=8=>a=4lei