Răspuns:
notam cu a= piersici,b =caise,c=prune
piersicile si caisele cantaresc 1000kg =>a+b=1000
caisele si prunele cantaresc 750kg=>b+c=750
piersicile si prunele cantaresc 750kg=>a+c=1100
adunam relatiile
a+b+b+c+a+c=1000+750+1100
2a+2b+2c=2850
dam factor comun 2
2(a+b+c)=2850=>a+b+c=2850:2=>piersici+caise+prune=1425 kg fructe in total
stim ca piersicile si caisele cantaresc 1000kg vom afla kg de prune =>1000+c=1425=>c=1425-1000=>c=425 kg prune
stim ca ,prunele si caisele cantaresc 750kg vom afla kg de piersici
=>a+750=1425=>a=1425-750=>a=675 kg piersici
stim ca piersicile si prunele cantaresc 750kg vom afla kg de caise
=>b+1100=1450=>b=1450-1100=>b=350 kg caise
425+675+350=1450 kg in total
pentru a afla canrtitatea totala de fructe vom aduna cele 3 relatii
ps + c = 1000
c + pr = 750
ps + pr = 1100
ps + c + c +pr + ps + pr = 1000 + 750 + 1100
2ps + 2c + 2 pr = 2850
2(ps + c + pr) = 2850
ps + c + pr = 1425 kg in total
pr = 1425 - (ps + c) = 1425 - 1000 = 425 kg de prune
c = (c + pr) - pr = 750 - 425 = 325 kg de caise
ps = (ps + c) - c = 1000 - 325 = 675 kg de piersici
