Предмет: Математика, автор: Л1и5к

решить систему уравнений графически {х-у=-8 {х+2у=-2 пожалуйста срочно

Ответы

Автор ответа: NiGhtWolFs
1
 \left \{ {{x-y=-8} \atop {x+2y=-2}} \right.  \left \{ {{y=8+x} \atop {y=-0,5x-1}} \right.

Теперь просто строим графики этих функций (см. фото в прикреплённых файлах) и ищем точку пересечения этих функций, координаты этой точки и будут решением системы. В данном случае пересекаются графики в точке с координатой (-6;2), т.е.:

 \left \{ {{x=-6} \atop {y=2}} \right.
Приложения:

Л1и5к: спасибо
NiGhtWolFs: Где же тут нарушение?
Л1и5к: ответ не верный в учебники такой ответ (4-2 )
NiGhtWolFs: В учебниках не всегда верные ответы, в Вашем учебнике как раз ответ (4;-2) не верный!
NiGhtWolFs: Подставив в исходную систему этот "Верный" ответ из учебника, Вы в этом убедитесь,
x-y=-8
x+2y=-2,
ответ по учебнику x=4, y=-2, т.е. судя по учебнику
4-(-2)=-8
4+2*(-2)=-2,
отсюда
6=-8
0=-2
Ну удачи тогда с вашими ответами из учебника)))
Л1и5к: так это ответ по учебнику ?
NiGhtWolFs: ??
Подставив ответ по учебнику x=4, y=-2, в исходную систему получается что
6=-8
0=-2
Сами решайте кому доверять
Л1и5к: это правильно ?
NiGhtWolFs: ну если по вашему
6=-8
0=-2,
то да :D
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