Question

Rezolvat prin metoda substitutiei :
$\left \{ {{X+3Y=1} \atop {2X+Y=7}} \right.$

Answer 1

$\left \{ {{x+3y=1} \atop {2x+y=7}} \right. \\ x+3y=1=>x=1-3y \\ 2(1-3y)+y=7 \\ 2-6y+y=7 \\ -5y=5=>y=-1 \\ x+3(-1)=1 \\ x-3=1=>x=4$

nu stiu daca am calculat corect adunarile/scaderile dar asta e metoda de rezolvare.