a) 4x - 6 = 14               
b) 30 - 8y = 22
c) 3u + 2 = 8
d) 4x - 7 = 3x + 5
e) 35 + 5x = 7- 2x 
f) 9y + 6 =13y - 2
g) x/5 + 3 = 2/5
h) 3x/7 + 1 = x/2 - 5
i) 2x + (5x - 2) = 7x + 9 - x
j) (7x + 4) - (-3x + 1) = 0
k) 2(3x- 4) - (x - 2) = 6 + 4(x - 3)

Répondre :

a) 4x - 6 = 14
4x=14+6
4x=20
x=20/4=5

b) 30 - 8y = 22
-8y=22-30
-8y=-8
y=1

c) 3u + 2 = 8
3u=8-2
3u=6
u=6/3=2

d) 4x - 7 = 3x + 5
4x-3x=5+7
x=12

e) 35 + 5x = 7- 2x 
5x+2x=7-35
7x=-28
x=-28/7=-4

f) 9y + 6 =13y - 2
9y-13y=-2-6
-4y=-8
y=8/4=2

g) x/5 + 3 = 2/5
x/5=2/5-3
x/5=2/5-15/5
x/5=-13/5
x=-13

h) 3x/7 + 1 = x/2 - 5
3x/7-x/2=-5-1
6x/14-7x/14=-6
-x/14=-6
x=6/14
x=84

i) 2x + (5x - 2) = 7x + 9 - x
2x+5x+2=7x+9-x
2x+5x-7x+x=9-2
x=7

j) (7x + 4) - (-3x + 1) = 0
7x+4+3x-1=0
7x+3x=1-4
10x=-3
x=-3/10

k) 2(3x- 4) - (x - 2) = 6 + 4(x - 3)
6x-8-x+2=6+4x-12
6x-x-4x=6-12+8-2
x=0
b)30-8y=22
-8y=-8
y=1

c)3u+2=8 
3u=6
u=2
d)4x-7=3x+5
4x-3x=5+7
x=12
e)35+5x=7-2x
35-7=-5x-2x
28=-7x
x=-4
f)9y+6=13y-2
6+2=13y-9y
8=4y
y=2


g)x/5+3=2/5
x/5=(-15+2)/5
x/5=-13/5
x=-13
h)3x/7+1=x/2-5
3x/7-x/2=-5-1
6-7/14x=-6
-1/14x=-6
x=-6*14
x=84

i)2x+5x-2=7x+9-x
-x=-2-9
x=11
j)7x+4+3x-1=0
10x=-3
x=-3/10
k) (6x-8)-x+2=6+4x-12
6x-8-x+2=6+4x-12
6x-x-4x=-6+6
x=0


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