Question

ДАЮ 35 БАЛОВ ПОМОГИТЕ ПОЖАЛУЙСТА! задание на ФОТО

Answer 1

Ответ:

1.(3;1) 2. (1;-2) 3. (3;2) 4. (1/5;1/3) 5. (4;2)

Объяснение:

1)
2x - 3y = 3

x - y = 2

2(y + 2) - 3y = 3

2y + 4 - 3y = 3

-y + 4 = 3

-y = 3 - 4

-y = -1

y = 1

x - 1 = 2

x = 2 + 1

x = 3

Решение: x = 3, y = 1.

2)

7u + 2v = 3

5u - v = 7

10u - 2v = 14

7u + 2v + 10u - 2v = 3 + 14

17u = 17

u = 1

5(1) - v = 7

5 - v = 7

-v = 2

v = -2

Решение: u = 1, v = -2.

3)

3x=y+7, 4y=3x-1

3x-y=7

3x-7=y

4(3x-7)=3x-1

12x-28=3x-1

12x-3x=28-1

9x=27

x=3

3(3)-y=7

9-y=7

-y=7-9

-y=-2

y=2

4)

5x - 6y = -1

2x + 3y = 14/10

10(2x + 3y) = 10(14/10)

20x + 30y = 14

3(5x - 6y) = 3(-1)

15x - 18y = -3

5(15x - 18y) = 5(-3)

3(20x + 30y) = 3(14)

75x - 90y = -15

60x + 90y = 42

(75x - 90y) + (60x + 90y) = -15 + 42

75x + 60x - 90y + 90y = 27

135x = 27

x = 27/135

x = 1/5

5(1/5) - 6y = -1

1 - 6y = -1

-6y = -2

y = (-2)/(-6)

y = 1/3

5)

(2x + 4y)/4 + 2 = 3y

2x + 4y + 8 = 12y

2x = 12y - 4y - 8

2x = 8y - 8

x = 4y - 4

(x - 3y)/2 + 3 = (2x + y)/5

(4y - 4 - 3y)/2 + 3 = (2(4y - 4) + y)/5

(y - 4)/2 + 3 = (8y - 8 + y)/5

5(y - 4) + 30 = 2(8y - 8 + y)

5y - 20 + 30 = 16y - 16 + 2y

5y + 10 = 18y - 16

10 = 13y - 16

26 = 13y

y = 2

x = 4y - 4

x = 4(2) - 4

x = 8 - 4

x = 4