Question

{5x+2y=1
{y-x=4
Пожалуйста помогите!!!!!!

Answer 1

$left { {{5x+2y=1} atop {y-x=4}} right.$
$left { {{5x+2*(4+x)=1} atop {y=4+x}} right.$
$left { {{5x+8+2x=1} atop {y=4+x}} right.$
$left { {{7x=1-8} atop {y=4+x}} right.$
$left { {{7x=-7} atop {y=4+x}} right.$
$left { {{x=-1} atop {y=4+(-1)}} right.$
$left { {{x=-1} atop {y=3}} right.$