Bonjour aidez moi svp !!! : a)12+x=5-13x 7x-8=3x+2 b)5-12x+13,5=-x +12+3x-7,5 C) x/5+11=-9 5-x/2=1/2. D) 11/5 x +2=0 11=5+3/2x E) 3x/2 + x/3-1=1/3 3/2 x +1 = x/
Question
1 Réponse
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1. Réponse maudmarine
Bonsoir,
a) 12 + x = 5 - 13x
x + 13x = 5 - 12
14x = - 7
x = - 7/14
x = - 1/2
7x - 8 = 3x + 2
7x - 3x = 2 + 8
4x = 10
x = 10/4
x = 5/2
b) 5 - 12x + 13,5 = - x + 12 + 3x - 7,5
- 12x + x - 3x = 12 - 7,5 - 5 - 13,5
- 14x = - 13,5
x = 13,5/14
C) x/5 + 11 = - 9
x/5 = - 9 - 11
x/5 = - 20
x/5 = - 100/5
x = - 100
5 - x/2 = 1/2.
- x/2 = 1/2 - 5
- x/2 = 1/2 - 10/2
- x = 1 - 10
- x = - 9
x = 9
D) 11/5x + 2 = 0
11/5x = - 2
11/5x = - 10/5
11x = - 10
x = - 10/11
11 = 5 + 3/2x
3/2x = 11 - 5
3/2x = 6
3/2x = 12/2
3x = 12
x = 12/3
x = 4
E) 3x/2 + x/3 - 1 = 1/3
9x/6 + 2x/6 = 2/6 + 6/6
9x + 2x = 2 + 6
11x = 8
x = 8/11
3/2x + 1 = x/4 - 1
3/2x - x/4 = - 1 - 1
6/4x - x/4 = - 4/4 - 4/4
6x - x = - 8
5x = - 8
x = - 8/5
F) 3x + 7 (8 - x) + 4 = 60 + x
3x + 56 - 7x + 4 = 60 + x
3x - 7x - x = 60 - 56 - 4
- 5x = 0
x = 0
G) 5 (x - 2) + 2 (1 - 3x) = 7x + 12
5x - 10 + 2 - 6x = 7x + 12
5x - 6x - 7x = 12 + 10 - 2
- 8x = 20
x = - 20/8
x = - 5/2
H) 4 (x - 1) - 3 (2 - x) = 2
4x - 4 - 6 + 3x = 2
4x + 3x = 2 + 4 + 6
7x = 12
x = 12/7.