Question

Folositi metoda substituției sau a reducerii : ​

Answer 1

Răspuns:

Spor!

Explicație pas cu pas:

Answer 2

Răspuns:

$\bf\red{\left \{ {{x=21} \atop {y=30}} \right. }$

Explicație pas cu pas:

$\left \{ {{x+y=51} \atop {2x+3y=132}} \right. \iff \left \{ {{x=51-y} \atop {2x+3y=132}} \right. \iff2x+3y=132 \iff 2(51-y)+3y=132\\\iff102-2y+3y=132\iff102+y=132\iff y=132-102\iff y=30\\\iff\left \{ {{x=51-y} \atop {y=30}} \right. \iff \left \{ {{x=51-30} \atop {y=30}} \right. \iff \bf\red{\left \{ {{x=21} \atop {y=30}} \right. }$