Question

Cum se rezolva?:

Se stie ca 3 lalele si 5 crizanteme costa 34 lei,iar 9 lalele si 4 crizanteme costa 47 de lei. Calculati cat costa o lalea si cat costa o crizantema.

Answer 1

[tex]x=laleaua\\ y=crizanteme\\ 3x+5y=34=\ \textgreater \ 3x=34-5y=\ \textgreater \ x=\frac{34-5y}{3}\\ 9x+4y=47\\ 9*\frac{34-5y}{3}+4y=47\\ 3(34-5y)+4y=47\\ 102-15y+4y=47\\ -11y=-55=\ \textgreater \ y=5 lei(crizantemele)\\ x=\frac{34-5*5}{3}=\frac{34-25}{3}=\frac{9}{3}=3lei(laleaua)[/tex]