Sagot :
Réponse :
Explications étape par étape
Bonjour,
a)
4+21 = 8x -3x
25 = 5x
x= 25/5 = 5
b)
1+80 = 7x +2x
81 = 9x
x = 81/9 = 9
c)
-3-3 = 5x -2x
-6 = 3x
x= -6/3 = -2
d)
5x-3x = -5 +3
2x = -2
x= -2/2 = -1
A)3x+4=8x-21
3x-8x=-21-4
-5x=-25
-5x/-5=-25/-5
X=5
B)-2x+1=7x-80
-2x-7x=-80-1
-9x=-81
-9x/-9=-81/-9
X=9
C)2x-3=5x+3
2x-5x=3+3
-3x=6
-3x/-3=6/-3
X=-2
D)5x-3=3x-5
5x-3x=-5+3
2x=-2
2x/2=-2/2
X=-1