Question

x+2y=4,
{
-1,5x+y=6
и еще вот это

x-y=-2
{
5x-2y=2

Answer 1

$left { {{x+2y=4} atop {-1,5x+y=6}} right.$
$left { {{x = 4-2y} atop {-1,5x+y=6}} right.$
-1,5 * (4-2y) + y = 6
-6 + 3y + y = 6
4y = 12
y = 3
$left { {{x=4-2y} atop {y = 3}} right.$
x = 4 - 2*3 
x = 4 - 6
x = -2
$left { {{x=-2} atop {y=3}} right.$
Ответ: (-2;3)

$left { {{x-y=-2} atop {5x-2y=2}} right.$
$left { {{x = y-2} atop {5x-2y=2}} right.$
5*(y-2) - 2y = 2
5y - 10 - 2y = 2
3y = 2 + 10
3y = 12
y = 4
$left { {{x=y-2} atop {y=4}} right.$
x = 4 - 2
x = 2
$left { {{x=2} atop {y=4}} right.$
Ответ: (2;4)

Answer 2

огромное спасибо! !!