Bonsoir
4(x + 2) = x - 1
<=> 4x + 8 - x + 1 = 0
<=> 3x + 9 = 0
<=> 3x = -9
<=> x = -9/3
<=> x = -3
3n - 1 = 2(n + 1)
<=> 3n - 1 = 2n + 2
<=> 3n - 1 - 2n - 2 = 0
<=> n - 3 = 0
<=> n = 3
5y + 1 = 3(y - 1) - 2
<=> 5y + 1 = 3y - 3 - 2
<=> 5y + 1 = 3y - 5
<=> 5y + 1 - 3y + 5 = 0
<=> 2y + 6 = 0
<=> 2y = -6
<=> y = -6/2
<=> y = -3
4(a + 1) - 5 = 6a + 5
<=> 4a + 4 - 5 - 6a - 5 = 0
<=> -2a - 6 = 0
<=> -2a = 6
<=> a = 6/(-2)
<=> a = -3
Voilà j'espère avoir pu t'aider ^^
