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2014-05-01T00:28:10+02:00
Exercice n°1
a) m + 17 = 45
   m = 45 - 17
   m = 28

b) x - 59 = 89
   x = 89 + 59
   x = 148

c) 74 - z = -32
    -z = -32 -74
    -z = -106
106 = z

d) t - 81 = -59
    t = 81 - 59
    t = 22

Exercice n°2
a) 7x = 84
x =  \frac{84}{7}
x = 12

b) -9 t = 81
    -t =  \frac{81}{9}
    -t= 9
9 = t

c)  \frac{a}{12} = 6
 \frac{1}{12} a = 6
a =  \frac{6*12}{1}
a = 72

d)  \frac{g}{6} = 21
 \frac{1}{6} g = 21
g =  \frac{21*6}{1}
g = 126

Exercice n°3
a) 8x + 7 = 31
8x = -7+31
8x = 24
x =  \frac{24}{8}
x = 3

b) -8d -2= 34
PGCD (8, 2, 34) = 2
-8d-2 = 34/2
-4d -1 = 17
-4d = 17 + 1
-4d = 18
d = - \frac{18}{4} = - \frac{9}{2}
d = -4,5
 
Exercice n° 4
a) 12y -9= 7y + 6
12y - 7y = 9 + 6
5y = 15
y =  \frac{15}{5}
y = 3

b) -12s +76 = 2s + 16
PGCD(12, 76, 2, 16) = 2
-12s + 76 = 2s +16/2
-6s + 38 = s + 8
- 7s = -30
s =  \frac{30}{7}