bonjour
a. x + 2 = 44
x = 44 - 2
x = 42
b . x + 3.6 = 4.2
x = 4.2 - 3.6
x = 0.6
je te laisse de c à h , c'est exactement la même chose, il te suffit de passer le chiffre de l'autre côté en changeant son signe .
i . 3 x + 2 = 44
3 x = 44 - 2
3 x = 42
x = 42/3 = 14
j. 2 x - 30 = 9
2 x = 9 + 30
2 x = 39
x = 39/2
k . 6 x + 12 = 11
6 x = 11 - 12
6 x = - 1
x = - 1/6
l. 7 x + 15 = 6 x + 3
7 x - 6 x = 3 - 15
x = - 12
m. 8 x + 3.2 = 9 x - 5.1
8 x - 9 x = - 5.1 - 3.2
- x = - 8.3
x = 8. 3
n . 9 x - 42 = - x + 8
9 x + x = 8 + 42
10 x = 50
x = 5
o. 12 x + 15 = 6 x + 3
12 x - 6 x = 3 - 15
6 x = - 12
x = - 2
p. 5 x - 32 = 2 x + 45
5 x - 2 x = 45 + 32
3 x = 77
x = 77/3
q. - 7 x - 8 = - 10 x + 19.3
- 7 x + 10 x = 19.3 + 8
3 x = 27.3
x = 273/30 = 91/10
r . 2 x + 7 = - 9 x + 158.8
2 x + 9 x = 158.8 - 7
11 x = 151.8
x = 1 518 /110 = 69/5
s. 4 ( 2 x - 1 ) = 7
8 x - 4 = 7
8 x = 7 + 4
8 x = 11
x = 11/8
t. 2 x + 3 = - 2 ( x - 5)
2 x + 3 = - 2 x + 10
2 x + 2 x = 10 - 3
4 x = 7
x = 7/4
u. 5 ( 4 + 3 x ) = 7 ( x - 1 )
20 + 15 x = 7 x - 7
15 x - 7 x = - 7 - 20
8 x = - 27
x = - 27/8
v. 5 ( x + 4) = 3 ( x + 5)
5 x + 20 = 3 x + 15
5 x - 3 x = 15 - 20
2 x = - 5
x = - 5/2
w. x - 6 ( 15 - x) = - 48
x - 90 + 6 x = - 48
7 x = - 48 + 90
7 x = 42
x = 6
x . 3.5 + ( 9 x + 2.5) = 32 - ( 3 x - 30.4 )
3.5 + 9 x + 2.5 = 32 - 3 x + 30.4
9 x + 3 x = 32 + 30.4 - 3.5 - 2.5
12 x = 56.4
x = 564/120 = 4.7
