Question

{3 x + 4 y=7
{9 x - 4 y = - 7

Answer 1

Ответ:

3x+y=7

9x-4y=-7

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y=7-3x

9x-4y=-7

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y=7-3x

9x-4(7-3x)=-7

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y=7-3x

9x-28+12x=-7

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y=7-3x

21x=28-7

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y=7-3x

21x=21

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y=7-3x

x=1

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y=7-3.1

x=1

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y=7-3

x=1

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y=4

x=1

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/x,y/=/1,4/

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