Question

под номером 2 систему и под номером 3

Answer 1

Задание 2:$left { {{4x-9y=3} atop {x=6-3y}} right.$
$left { {{4(6-3y)-9y=3} atop {x=6-3y}} right.$
$left { {{24-12y-9y=3} atop {x=6-3y}} right.$
$left { {{24-3=12y+9y} atop {x=6-3y}} right.$
$left { {{21=21y} atop {x=6-3y}} right.$
$left { {{y=1} atop {x=6-3y}} right.$
$left { {{y=1} atop {x=6-3*1}} right.$
$left { {{y=1} atop {x=3}} right.$