Question

Помогите пожалуйста сделать б) и в)

Answer 1

Ответ:

Ответ в объяснении

Объяснение:

( X + 2 )*( Y + 1 ) = 12

X + 2Y = 6 ; X = 6 - 2Y

( 6 - 2Y + 2 )*( Y + 1 ) = 12

( 8 - 2Y )*( Y + 1 ) = 12

8Y + 8 - 2Y^2 - 2Y = 12

- 2Y^2 + 6Y - 4 = 0

- 2 * ( Y^2 - 3Y + 2 ) = 0

D = 9 - 8 = 1 ; √ D = 1

Y1 = ( 3 + 1 ) : 2 = 2

Y2 = ( 3 - 1 ) : 2 = 1

X1 = 6 - 4 = 2

X2 = 6 - 2 = 4

ОТВЕТ ( 2 ; 2 ) ; ( 4 ; 1 )

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X^2 + Y^2 = 10

XY = - 3

X = ( - 3 / Y ) ; X^2 = 9 / Y^2

( 9 / Y^2 ) + Y^2 = 10

( 9 + Y^4 ) / Y^2 = 10 ( Y ≠ 0 )

9 + Y^4 = 10Y^2

Y^4 - 10Y^2 + 9 = 0

Y^2 = A ; A > 0

A^2 - 10A + 9 = 0

D = 100 - 36 = 64 ; √ D = 8

A1 = ( 10 + 8 ) : 2 = 9

A2 = ( 10 - 8 ) : 2 = 1

Y^2 = 9 ===> Y (1 /2 ) = ( + / - ) 3

Y^2 = 1 ===> Y ( 3/4 ) = ( +/ - ) 1

X^2 = 9 / Y^2

X^2 = 9 / 9 = 1 ===> X ( 1/2 ) = ( + / - ) 1

X^2 = 9 / 1 = 9 ===> X ( 3/4 ) = ( + / - ) 3

ОТВЕТ ( 1 ; 3 ); ( - 1 ; - 3 ); ( 3 ; 1 ) ; ( - 3 ; - 1 )