Réponse :
Bonjour
Explications étape par étape :
Oz = 0
z = 0
3z -10 = 11
3z = +10 +11
3z = 22
z = 22/3
2 + 3z = 17
3z = -2 + 17
3z = 15
z = 15/3
z = 5
7 -3x = -22
-3x = -7 -22
-3x = -29
x = + 29/3
5x = 3x +3
5x -3x = 3
2x = 3
x = 3/2
7x + 1 = 4x
7x -4x = -1
3x = -1
x = -1/3
4 -7y = 10y
-7y - 10y = -4
-17y = -4
y = +4/17
4(x + 5) = 10x + 3
4x + 20 = 10x + 3
4x - 10x = -20 + 3
-6x = -17
x = + 17/6
