bonjour j'aimerais que l'on m'explique l'exo n°2 et aussi l'équation au dessus s'il vous plait

Bonsoir,

(x + 3)/(x - 1) = 5/6 - (-1/2)
(x + 3)/(x - 1) = 5/6 + 3/6
(x + 3)/(x - 1) = 8/6

Avec x - 1 ≠ 0
x ≠ 1

6(x + 3) = 8(x - 1)
6x + 18 = 8x - 8
18 + 8 = 8x - 6x
26 = 2x
x = 26/2
x = 13

Exercice 2 :

n : un nombre

A) 4n - 7 = 53
4n = 53 + 7
n = 60/4
n = 15

B) 3n - 4 = 20
3n = 20 + 4
n = 24/3
n = 8

C) n/3 + 6 = 9
n/3 = 9 - 6
n = 3 x 3
n = 9

D) 3n/4 - 1 = 8
3n/4 = 8 + 1
n = 4/3 x 9
n = 12

E) 3(n + 10) = 5n
3n + 30 = 5n
30 = 5n - 3n
2n = 30
n = 30/2
n = 15

F) 5n + 10 = 7n - 6
10 + 6 = 7n - 5n
16 = 2n
n = 16/2
n = 8

G) 3n + 8 = 0
3n = -8
n = -8/3