Question

Решите методом подстановки:
4x-9y=3,
X+3y=6.

Answer 1

$left { {{4x-9y=3} atop {x+3y=6}} right. \ \ left { {{4(6-3y)-9y=3} atop {x=6-3y}} right. \ \ left { {{24-12y-9y=3} atop {x=6-3y}} right. \ \ left { {{-21y=-21} atop {x=6-3y}} right. \ \ left { {{y=1} atop {x=6-3=1}} right. \ \ x=3, y=1$