Bonjour , j'aurais besoin d'aide pour ces équations, merci ^^ (toute aide sera utile !) a) 5x-7 = 8 b) -2 = 18+10y c) 7+9y = -29 d) 3(x-1) = 3 e) 12-6x = 3/2 f
Mathématiques
zinedine701
Question
Bonjour , j'aurais besoin d'aide pour ces équations, merci ^^ (toute aide sera utile !)
a) 5x-7 = 8
b) -2 = 18+10y
c) 7+9y = -29
d) 3(x-1) = 3
e) 12-6x = 3/2
f) 5/3x + 1/5 = 2/3x - 1/5
g) 7x+3 = -4+7(x+1)
h) 2(x-1) = x+3+x
Ps: x= lettre x
a) 5x-7 = 8
b) -2 = 18+10y
c) 7+9y = -29
d) 3(x-1) = 3
e) 12-6x = 3/2
f) 5/3x + 1/5 = 2/3x - 1/5
g) 7x+3 = -4+7(x+1)
h) 2(x-1) = x+3+x
Ps: x= lettre x
1 Réponse
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1. Réponse maudmarine
Bonjour,
a) 5x-7 = 8
5x = 8 + 7
5x = 15
x = 15/5
x = 3
b) -2 = 18+10y
10y = - 18 - 2
10y = - 20
y = - 20/10
y = - 2
c) 7+9y = -29
9y = - 29 - 7
9y = - 36
y = - 36/9
y = - 4
d) 3(x-1) = 3
3x - 3 = 3
3x = 3 + 3
3x = 6
x = 6/3
x = 2
e) 12-6x = 3/2
- 6x = 3/2 - 12
- 12/2x = 3/2 - 24/2
- 12x = 3 - 24
- 12x = - 21
x = 21/12
x = 7/4
f) 5/3x + 1/5 = 2/3x - 1/5
5/3x - 2/3x = - 1/5 - 1/5
3/3x = - 2/5
x = - 2/5
g) 7x+3 = -4+7(x+1)
7x + 3 = - 4 + 7x + 7
7x - 7x = - 4 + 7 - 3
0x = 0 --> Impossible
h) 2(x-1) = x+3+x
2x - 2 = x + x + 3
2x - 2 = 2x + 3
2x - 2x = 3 + 2
0x = 5 --> Impossible