Question

4 creioane si 2 stilori costa 38 lei 3 creioane si 3 stilouri costa 51 lei Cat costa 2 creioane plus 2 stilouri?

Answer 1

creioane - x
stilouri - y

[tex] \left \{ {{4*x+2*y=38} \atop {3*x+3*y=51}} \right. \ \textless \ =\ \textgreater \ \left \{ {{2*x+y=19} \atop {3*x+3*y=51}} \right. \ \textless \ =\ \textgreater \ \left \{ {{6*x+3*y=57} \atop {3*x+3*y=51}} \right. \ \textless \ =\ \textgreater \ \\ \left \{ {{3*x=6} \atop {2*x+y=19}} \right. \ \textless \ =\ \textgreater \ \left \{ {{x=2} \atop {y=15}} \right. \\ Atunci:\\ 2*x+2*y=2*2+2*15=4+30=34\\ Raspuns:34lei. [/tex]