5.122 Найдите корень уравнения и выполните проверку: a) -30(x - 21) = -180; б) (15 - 9x)4 = 204; 9 51 B) 4x 147 5.123 Решите уравнение: a) -36x + 660 = -3x; 6) 92 = -350 + 4z; 5.124 Решите уравнение: a) -5(-y + 9) = y + 10; б) т 17 = (m + 4)(-9); в) 17 4(m + 11) = 43; г) (3,6 – 0,2x)4,9 = 9,8; 5 д) (7х - 3,4)9 = 13,5; 1 x = 3,5. 5 e) x + x 3 6 в) -8x + 83 = 3x – 49; г) 43 7z = 27 9z; д) 41 + 23у = 341 +1 e) 21x 34 = 12x - г) -7(4х + 2) 3 = −17; д) -4,8у + 7,2 = 3(2,4y + 4,8); e) -5(0,6y – 1,8) = −2y + 8,5.

а)

-30(x - 21) = -180

-30x + 630 = -180

-30x = -180 - 630

-30x = -810

x = -810 / -30

x = 27

б)

(15 - 9x)4 = 204

60 - 36x = 204

-36x = 204 - 60

-36x = 144

x = 144 / -36

x = -4

в) \[\frac{9}{4}x - \frac{5}{14} = \frac{1}{7}\] \[\frac{9}{4}x = \frac{1}{7} + \frac{5}{14}\] \[\frac{9}{4}x = \frac{2}{14} + \frac{5}{14}\] \[\frac{9}{4}x = \frac{7}{14}\] \[\frac{9}{4}x = \frac{1}{2}\] \[x = \frac{1}{2} \cdot \frac{4}{9}\] \[x = \frac{4}{18}\] \[x = \frac{2}{9}\]

x = 2/9

г)

(3,6 – 0,2x)4,9 = 9,8

17,64 - 0,98x = 9,8

-0,98x = 9,8 - 17,64

-0,98x = -7,84

x = -7,84 / -0,98

x = 8

д)

(7x - 3,4)9 = 13,5

63x - 30,6 = 13,5

63x = 13,5 + 30,6

63x = 44,1

x = 44,1 / 63

x = 0,7

е) \[\frac{1}{3}x + \frac{5}{6}x = 3,5\] \[\frac{2}{6}x + \frac{5}{6}x = 3,5\] \[\frac{7}{6}x = 3,5\] \[x = 3,5 \cdot \frac{6}{7}\] \[x = \frac{3,5 \cdot 6}{7}\] \[x = \frac{21}{7}\]

x = 3

а)

-36x + 660 = -3x

-36x + 3x = -660

-33x = -660

x = -660 / -33

x = 20

б)

9z = -350 + 4z

9z - 4z = -350

5z = -350

z = -350 / 5

z = -70

в)

-8x + 83 = 3x – 49

-8x - 3x = -49 - 83

-11x = -132

x = -132 / -11

x = 12

г)

43 - 7z = 27 - 9z

-7z + 9z = 27 - 43

2z = -16

z = -16 / 2

z = -8

д)

41 + 23у = 341 + 1

23y = 342 - 41

23y = 301

y = 301 / 23

y = 13,087 (примерно)

е)

21x - 34 = 12x -

21x - 12x = 34

9x = 34

x = 34 / 9

x = 3,778 (примерно)

а)

-5(-y + 9) = y + 10

5y - 45 = y + 10

5y - y = 10 + 45

4y = 55

y = 55 / 4

y = 13,75

б)

m - 17 = (m + 4)(-9)

m - 17 = -9m - 36

m + 9m = -36 + 17

10m = -19

m = -19 / 10

m = -1,9

в)

17 - 4(m + 11) = 43

17 - 4m - 44 = 43

-4m = 43 - 17 + 44

-4m = 70

m = 70 / -4

m = -17,5

г)

-7(4х + 2) - 3 = −17

-28x - 14 - 3 = -17

-28x = -17 + 14 + 3

-28x = 0

x = 0

д)

-4,8у + 7,2 = 3(2,4y + 4,8)

-4,8y + 7,2 = 7,2y + 14,4

-4,8y - 7,2y = 14,4 - 7,2

-12y = 7,2

y = 7,2 / -12

y = -0,6

е)

-5(0,6y – 1,8) = −2y + 8,5

-3y + 9 = -2y + 8,5

-3y + 2y = 8,5 - 9

-y = -0,5

y = 0,5