Question

помогите пожалуйста очень надо даю 100 балов​

Answer 1

1.

1)

$x + y =4 \\ 3x + y = 6 \\ \\ y = 4 - x \\ 3x + 4 - x = 6 \\ \\ 2x = 6 - 4 \\ 2x = 2 \\ x = 2 \div 2 \\ x = 1 \\ \\ y = 4 - 1 = 3$

Ответ: ( 1 ; 3 )

2)

$x - y = 0 \\ x - 2y = 8 \\ \\ x = y \\ y - 2y = 8 \\ - y = 8 \\ y = - 8 \\ \\ x = y = - 8$

Ответ: ( - 8 ; - 8 )

3)

$y - x = - 5 \\ 2x + y = 4 \\ \\ y = x - 5 \\ 2x + x - 5 = 4 \\ 3x = 4 + 5 \\ 3x = 9 \\ x = 9 \div 3 \\ x = 3 \\ \\ y = 3 - 5 = - 2$

Ответ: ( 3 ; - 2 )

4)

$3x - 2y = 6 \\ x + 2y = 2 \\ \\ 3(2 - 2y) - 2y = 6\\ x = 2 - 2y \\ \\ 6 - 6y - 2y = 6 \\ - 8y = 6 - 6 \\ - 8y = 0 \\ y = 0 \\ \\ x = 2 - 2 \times 0 = 2$

Ответ: ( 2 ; 0 )

2.

$x - y = 3 \\ 3x + 2y = 14 \\ \\ x = y + 3 \\ 3(y + 3) + 2y = 14 \\ \\ 3y + 9 + 2y = 14 \\ 5y = 14 - 9 \\ 5y = 5 \\ y = 5 \div 5 \\ y = 1 \\ \\ x = 1 + 3 = 4$

Ответ: ( 4 ; 1 )