Pouvez vous m’aider sur cet exercice

Bonsoir,

a. 2x/3 + 5 = 2x/5 + 6

10x/15 + 75/15 = 6x/15 + 90/15

10x - 6x = 90 - 75

4x= 15

x = 15/4

x = 3,74

b. 3x/5 - (2x - 7) / 15 + x /3 = 0

9x/15 - (2x - 7) / 15 + 5x/15 = 0

9x - 2x + 7 + 5x = 0

9x - 2x + 5x = - 7

12x = - 7

x = - 7/12

c. (3x - 1) / 2 - (5x - 2) / 3 + (7x - 3) / 4 = 24/5

(90x - 30) / 60 - (100x - 40) / 60 + (105x - 45) / 60 = 288/60

90x - 30 - 100x + 40 + 105x - 45 = 288

90x - 100x + 105x = 288 + 30 + 45 - 40

95x = 323

x = 323/95

x = 3,4

d. (5x + 1) / 5 - (3x - 1) / 4 = [2 (4x + 1)] / 5

(20x + 4) / 20 - (15x - 5) / 20 = (8x + 2) / 5

20x + 4) / 20 - (15x - 5) / 20 = (32x + 8) / 20

20x + 4 - 15x - 5 = 32x + 8

20x - 15x - 32x = 8 - 4 + 5

- 27x = 9

x = - 9/27

x = - 1/3

e. (2x + 1) / 3 - (x - 1) / 5 = (7x - 12) / 15

(10x + 5) / 15 - (3x - 3) / 15 = (7x - 12) / 15

10x + 5 - 3x + 3 = 7x - 12

10x - 3x - 7x = - 12 - 5 - 3

0x = ---