Question

7 pungi cu malai si 6 pungi cu faina cantaresc 53 kg , iar 4 pungi cu faina si 7 pungi cu malai cantaresc 47 kg . Cat cantaresc 3 pungi cu malai si 3 pungi cu faina ?

Answer 1

7m + 6f = 53
4f + 7m =47
14m + 10f = 53+47=100
2(7m + 5f)=100

7m + 5f =100:2=50
7m + 4f=47
scadem
=>
f=50-47
f=3

7m+12=47
7m=47-12=35
m=5

3m+3f=3x5+3x3=15+9=24

unde m=punga malai, f=punga faina

Answer 2

pungi malai=A
pungi faina=B
7A+6B=53kg
4B+7A=47kg
7A-7A+6B-4B=53-47
2B=6kg
B=3kg(atata cantareste o punga cu faina)
7A+6*3=53KG
7a+18=53KG
7a=35kg
A=5kg(atata cantareste o punga cu malai)
3*3+3*5=9+15=24kg(atata cantareste 3pungi de malai si 3 de faina)