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 = ---
