Résoudre les équations suivantes. a) 2 (x +3) = 3 (x + 2) b) 3 ( 5 - 2x) = 2 (x - 1) c) 3+2 (x -1) = 3x + 6 d) 5 x - 2 (3x +1) = 3 (x - 7)
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Question
Résoudre les équations suivantes.
a) 2 (x +3) = 3 (x + 2)
b) 3 ( 5 - 2x) = 2 (x - 1)
c) 3+2 (x -1) = 3x + 6
d) 5x - 2 (3x +1) = 3 (x - 7)
1 Réponse
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1. Réponse Stéphanie972
a. 2 ( x + 3 ) = 3 ( x + 2 )
2x + 6 = 3x + 6
2x + 6 - 3x = 6
-x = 6 - 6
x = 0
b. 3 ( 5 - 2x) = 2 (x - 1)
15 - 6x = 2x -2
15 = 2x -2 + 6x
15 + 2 = 8x
17 = 8x
x = 17/8
c. 3+2 (x -1) = 3x + 6
3 + 2x -2 = 3x+6
2x + 1 = 3x +6
-6 +1 = 3x -2x
-5 = x
x = -5
d. 5x - 2 (3x +1) = 3 (x - 7)
5x - 6x - 2 = 3x -21
-1x -2 = 3x -21
-2 = 3x-21 + 1x
-2 +21 = 4x
19 = 4x
x = 19/4
x= 4.75