Question

9x+4y=-2и
8=-x-y
Решить СИСТЕМУ ​

Answer 1

Ответ:

9x+4y=-2

-x-y=8

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9x+4y=-2

-x=8+y | •(-1)

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9x+4y=-2

x=-8-y

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9(-8-y)+4y=-2

-72-9y+4y=-2

-5y=-2+72

-5y=70

y=70:-(5)

y=-14

x=-8+14=6

Ответ:(6;-14)

Answer 2

Ответ:

(x;y) = (6;-14)

Объяснение:

$\displaystyle \left \{ {{9x+4y=-2} \atop {-x-y=8}} \right. < = > \left \{ {{9x+4(-8-x)=-2} \atop {y=-8-x}} \right. < = > \left \{ {{9x-32-4x=-2} \atop {y=-(8+x)}} \right. < = >$
$< = > \displaystyle \left \{ {{5x=30|:5} \atop {y=-(8+x)}} \right. < = > \left \{ {{x=6} \atop {y=-(8+6)}} \right. < = > \left \{ {{x=6} \atop {y=-14}} \right.$