Найдите корни уравнения 3 (x-5) = x+3 1,5 (x+8) = -4x+1 3/4 (x+8) = 2x+1

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Математика

2 декабря, 00:00

Найдите корни уравнения 3 (x-5) = x+3 1,5 (x+8) = -4x+1 3/4 (x+8) = 2x+1

+4

Ответы (1)

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Тимур Некрасов · Answer 1

1) 3 (x - 5) = x + 3

3x - 15 = x + 3

3x - x - 15 = 3

3x - x = 3 + 15

3x - x = 18

x (3 - 1) = 18

2x = 18

x = 18/2

x = 9

Ответ: 9

2) 1,5 (x + 8) = - 4x + 1

1 5/10 (x + 8) = - 4x + 1

1 1/2 (x + 8) = - 4x + 1

3/2 (x + 8) = - 4x + 1

3/2x + 8 * 3/2 = - 4x + 1

3/2x + 3 * 8/2 = - 4x + 1

3/2x + 3 * 4 = - 4x + 1

3/2x + 12 = - 4x + 1

3/2x + 4x = 1 - 12

x (3/2 + 4) = 1 - 12

x (3/2 + 8/2) = 1 - 12

x (3 + 8) / 2 = 1 - 12

11/2x = 1 - 12

11/2x = - (-1 + 12)

11/2x = - (12 - 1)

11/2x = - 11

x = - 11 : 11/2

x = - 11 * 2/11

x = - 2 * 11/11

x = - 2 * 1

x = - 2

Ответ: - 2

3) 3/4 (x + 8) = 2x + 1

3/4x + 8 * 3/4 = 2x + 1

3/4x + 3 * 8/4 = 2x + 1

3/4x + 3 * 2 = 2x + 1

3/4x + 6 = 2x + 1

6 = 2x + 1 - 3/4x

6 - 1 = 2x - 3/4x

5 = 2x - 3/4x

5 = x (2 - 3/4)

5 = x (8/4 - 3/4)

5 = x (8 - 3) / 4

5 = x5/4

x = 5 : 5/4

x = 5 * 4/5

x = 4 * 5/5

x = 4 * 1

x = 4

Ответ: 4