38. 5a +3(2a - 5) = 4(12 - a) - 3; =
39. 5(9t - 3(2t - 4)) + 12 = 4(t + 29); =
40. 2(5x -2(x + 3)) - 15 = 17 + x + 11.=

1)

5a + 3(2a - 5) = 4(12 - a) - 3

5a + 6a - 15 = 48 - 4a - 3

11a - 15 = 45 - 4a

11a + 4a = 45 + 15

15a = 60

a = 4

ответ: 4.

2)

(9t - 3(2t - 4)) + 12 = 4(t + 29)

3t + 12 + 12 = 4t + 116

3t - 4t = 116 - 24

-t = 92

t = -92

ответ: -92.

3)

2(5x -2(x + 3)) - 15 = 17 + x + 11

6x - 12 - 15 = 28 + x

6x - x = 28 + 27

5x = 55

x = 11

ответ: 11.