Question

3 pixuri si 4 stilouri costa 44 lei iar 5 pixuri si 2 stilouri costa 50 lei.Cat costa un pix si un stilou?

Answer 1

Un pix costa 8 lei,iar un stilou 5 lei. PROBA:8•3+4•5=44;24+20=44;44=44 (A).________5•8+2•5=50;40+10=50;50=50 (A).

Answer 2

p - pixuri
s - stilouri
[tex] \left \{ {{3p+4s=44} \atop {5p+2s=50}} \right. \\ \\ \left \{ {{3p+4s=44} \atop {2s=50-5p}} \right. \\ \\ \left \{ {{3p+4*\frac{50-5p}{2}=44} \atop {s= \frac{50-5p}{2} }} \right. \\ \\ \left \{ {{3p+2*(50-5p)=44} \atop {s= \frac{50-5p}{2} }} \right. \\ \\ \left \{ {{3p+100-10p=44} \atop {s= \frac{50-5p}{2} }} \right. \\ \\ \left \{ {{100-44=7p} \atop {s= \frac{50-5p}{2} }} \right. \\ \\ \left \{ {{56=7p} \atop {s= \frac{50-5p}{2} }} \right. \\ \\ \left \{ {{p=8} \atop {s=\frac{50-5*8}{2}}} \right.[/tex]
[tex] \left \{ {{p=8} \atop {s=\frac{50-40}{2} }} \right.\\ \\ \left \{ {{p=8} \atop {s=\frac{10}{2} }} \right.\\ \\ \left \{ {{p=8} \atop {s=5 }} \right.[/tex]