Question

sistem de 2x+y=8 si 2x-3y= -8.. help

Answer 1

2x + y = 8              (1)
2x -3y = - 8            (2)
din (1) - (2)  ⇒  4y = 16    y = 4    x = 2

Answer 2

$\displaystyle \left \{ {{2x+y=8 |\cdot3} \atop {2x-3y= -8}} \right \\ -------- \\ \\ \left \{ {{6x+3y=24} \atop {2x-3y= -8}} \right. \\ \\ 8x \ \ \ \ | \ \ \ \ 16 \\ x=16:8 \\ \boxed{x=2} \\ \\ 2\cdot2+y=8 \\ 4+y=8 \\ \boxed{y=4}$