Question

Решите методом подстановки
1) x+2y = 4
3х – 4 y = 2​

Answer 1

$\left \{ {{x+2y=4} \atop {3x-4y=2}} \right. \\\\\left \{ {{x=4-2y} \atop {3x-4y=2}} \right. \\3(4-2y)-4y=2\\12-6y-4y=2\\-10y=10\\y=-1\\x=2y-4=-2-4=-6$