Question

а) х+у=11
2х-у=-5

б) 5х-4у=8
х-4=2
Помогите пожалуйста! Полный ответ

Answer 1

$left { {{x+y=11} atop {2x-y=-5}} right. + left { {{x+y=11} atop {2x-y=-5}} right. (x + y) + (2y - 11) = 11 - 5 3x = 6 x = 2 (2) + y = 11 y = 9 ( 2 ; 9 )$

$left { {{5x - 4y = 8} atop {x - 4 = 2}} right. left { {{5x - 4y = 8} atop {x - 6 = 0}} right. left { {{5(6) - 4y = 8} atop {x=6}} right. left { {{-4y + 22 = 0} atop {x=6}} right. left { {{y=5.5} atop {x=6}} right. ( 6 ; 5.5 )$