Question

Nu ma pricep deloc la astfel de probleme,va rog mult ajutati-ma!

Answer 1

$\left \{ {{3s + 5c = 43} \atop {2s + 4c = 32}} \right.$
scadem a doua ecuatie din prima ⇒ s + c = 9 ⇔ 3s + 3c = 27 (*)
daca revenim la ecuatia initiala, unde 3s + 5c = 32, scadem din ea ecuatia (*)
⇒ 2c = 5 ⇒ c = $\frac{5}{2}$

Answer 2

Pai face un sistem {3kg struguri+5kg cirese=43lei | * 2 {2kg struguri+4kg cirese=32lei | * (-3) <=> {6kg struguri +10 kg cirese=86 lei {-6kg struguri-12kg cirese=-96lei _________________________________ /-2kg cirese=-10lei | * (-1) 2k cirese=10 lei 1kg cirese=5lei