Question

х+3у=2;2х+3y=7
2х-у=2;3х-2у=3 метод подстановки

Answer 1

Ответ:

1. x = 5 ; y = - 1.

2. x = 1 ; y = 0.

Объяснение:

1.

{x + 3y = 2

{2x + 3y = 7

{x=2-3y

{2x+3y=7

2 · ( 2 - 3y ) + 3y = 7

4 - 6y + 3y = 7

4 - 3y = 7

- 3y = 7 - 4

- 3y = 3

y = - 1

x = 2 - 3 · ( - 1 ) = 2 + 3 = 5

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2.

{2x - y = 2

{3x - 2y = 3

{y = - ( 2 - 2x )

{3x - 2y = 3

{y = - 2 + 2x

{3x - 2y = 3

3x - 2 · ( - 2 + 2x ) = 3

3x + 4 - 4x = 3

- x + 4 = 3

- x =3 - 4

x = 1

y = - 2 + 2 · 1 = 0