Question

СРОЧНО РОЗВ‘ЯЗАТИ МЕТОДОМ ПІДСТАНОВКИ

Answer 1

Ответ:на фото

Объяснение:

Answer 2

1.

$\displaystyle\bf\\\left \{ {{x - y = 2} \atop {2x - 3y = 5 }} \right. \\ \displaystyle\bf\\\left \{ {{x = y + 2} \atop {2(y + 2) - 3y = 5 }} \right. \\ \\ 2y + 4 - 3y = 5 \\ - y = 5 - 4 \\ - y = 1 \\ y = - 1 \\ \\ x = - 1 + 2 \\ x= 1$

Ответ: ( 1 ; - 1 )

2.

$\displaystyle\bf\\\left \{ {{x + y = 2} \atop {5x + 2y = 1 }} \right. \\ \displaystyle\bf\\\left \{ {{y = 2 - x} \atop {5x + 2(2 - x) = 1 }} \right. \\ \\ 5x + 4 -2 x = 1 \\ 3x = 1 - 4 \\ 3x = - 3 \\ x = - 3 \div 3 \\ x = - 1 \\ \\ y = 2 - ( - 1) \\ y = 2 + 1 \\ y = 3$

Ответ: ( - 1 ; 3 )

3.

$\displaystyle\bf\\\left \{ {{2x - y = 5} \atop {2x + 3y = - 7 }} \right. \\ \displaystyle\bf\\\left \{ {{y = 2x - 5} \atop {2x + 3(2x - 5) = - 7 }} \right. \\ \\ 2x + 6x - 15 = - 7 \\ 8x = - 7 + 15 \\ 8x = 8 \\ x = 8 \div 8 \\ x = 1 \\ \\ y = 2 \times 1 - 5 \\ y = 2 - 5 \\ y = - 3$

Ответ: ( 1 ; - 3 )