Question

СРОЧНО!!! решить системы уравнений ГРАФИЧЕСКИ!!! ДАЮ ВСЕ БАЛЛЫЫЫЫЫ
x+y=4
x-2y=-2
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x-y=3
3x-y=13

Answer 1

$\left \{ {{x=4-y} \atop {x-2y=-2}} \right. \\ 4-y-2y=-2 \\ 4-3y=-2 \\ -3y=-2-4 \\ -3y=-6 \\ y=2 \\ x=4-2 \\ x=2 \\ (x y)=(2 , 2) \left \{ {{2+2=4 \atop {-2-2*2=-2}} \right. \left \{ {{4=4} \atop {-2=-2.}} \right.\ \left \{ {{x-y=3} \atop {3x-y=13}} \right. \left \{ {{x=3+y} \atop {3x-y=13}} \right. \\ 3(3+y)-y=13 \\ 9+3y-y=13 \\ 9+2y=13 \\ 2y=13-9 \\ 2y=4 \\ y=2 \\ x=3+2 \\ x=5 \\ (x,y)=(5,2) \left \{ {{5-2=3} \atop {3*5-2=13}} \right.$