resoudre l'equations suivante (du 1er degré nivau 4eme) a) 3x= x-55 / 4 b) 1-x/5 + x+1/4=3x/20 +1 c) x+2/2 - x-1/3=x merci!
Mathématiques
Zoputan555
Question
resoudre l'equations suivante (du 1er degré nivau 4eme)
a) 3x= x-55 / 4
b) 1-x/5 + x+1/4=3x/20 +1
c) x+2/2 - x-1/3=x
merci!
1 Réponse
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1. Réponse maudmarine
a) 3x= x - 55 / 4
12/4x = 4/4x - 55/4
12/4x - 4/4x = - 55/4
8/4x = - 55/4
8x = - 55
x = - 55/8
x = - 6,875
b) 1-x/5 + x+1/4 = 3x/20 + 1
20/20 - 4/20x + 20/20x + 5/20 = 3/20x + 20/20
- 4/20x + 20/20x - 3/20x = 20/20 - 20/20 - 5/20
13/20x = - 5/20
13x = - 5
x = - 5/13
c) x + 2/2 - x - 1/3 = x
6/6x + 6/6 - 6/6x - 2/6 = 6/6x
6/6x - 6/6x - 6/6x = - 6/6 + 2/6
- 6/6x = - 4/6
- 6x = - 4
x = 4/6
x = 2/3