Question

Решите пожалуйста алгебру....
1.Решите систему уравнений способом подстановки:
{x+5y=7
{3x-2y=4
2.Решите систему уравнений способом подстановки:
{5x-y=4
{2x+3y=22

Answer 1

$1)\left \{ {{x+5y=7} \atop {3x-2y=4}} \right.\\\\\left \{ {{x=7-5y} \atop {3*(7-5y)-2y=4}} \right. \\\\\left \{ {{x=7-5y} \atop {21-15y-2y=4}} \right.\\\\\left \{ {{x=7-5y} \atop {-17y=-17}} \right.\\\\\left \{ {{y=1} \atop {x=7-5*1}} \right.\\\\\left \{ {{y=1} \atop {x=2}} \right. \\\\Otvet:\boxed{(2;1)}$

$2)\left \{ {{5x-y=4} \atop {2x+3y=22}} \right.\\\\\left \{ {{y=5x-4} \atop {2x+3*(5x-4)=22}} \right.\\\\\left \{ {{y=5x-4} \atop {2x-12+15x=22}} \right.\\\\\left \{ {{y=5x-4} \atop {17x=34}} \right. \\\\\left \{ {{x=2} \atop {y=5*2-4}} \right.\\\\\left \{ {{x=2} \atop {y=6}} \right.\\\\Otvet:\boxed{(2;6)}$