Réponse :
Bonsoir
Explications étape par étape
ex3)
A)
3x + 7 = 34
3x = 34 - 7
3x = 27
x = 27/3
x = 9
B)
2 + 4y = -6
4y = -6 - 2
4y = -8
y = -8/4
y = -2
c)
-3 -2a = 7
-2a = 7 +3
-2a = 10
a = -10/2
a = -5
d)
-3 = -3t -12
3t = -12 + 3
3t = -9
t = -9/3
t = -3
ex 20)
z - 8 + z + z + 3 = 61
3z - 5 = 61
3z = 61 + 5
3z = 66
z = 66/3
z = 22