Question

1.Решить систему
4x+y=10
2x-3y=12

Answer 1

у=10-4х
2х-30+12х=12
14х=42
х=3
у=10-4*3=10-12=-2
ответ:х=3, у=-2

Answer 2

$\left \{ {{4x+y=10} \atop {2x-3y=12}} \right. \\ \left \{ {{12x+3y=30} \atop {2x-3y=12}} \right. \\ 12x+3y+2x-3y=30+12 \\ 14x=42 \\ x = 3 \\ \\ 4x+y=10 \\ 12+y=10 \\ y=10-12 \\ y=-2$