Voici quelques équations : a) 4x+3=3x - 5 ; b) -2x+7 = 3x-13 c) -3x+4=6x+5 d) 4-7x= -3x+1 e) 3 (x-8)=4x+5 f) -4(2+x) = 3x-5 g) 9(2-2x)= - (7x+1) h) -3 (4+x) + 3
Mathématiques
Mwaa6633
Question
Voici quelques équations :
a) 4x+3=3x - 5 ;
b) -2x+7 = 3x-13
c) -3x+4=6x+5
d) 4-7x= -3x+1
e) 3 (x-8)=4x+5
f) -4(2+x) = 3x-5
g) 9(2-2x)= - (7x+1)
h) -3 (4+x) + 3x = 6(x+1)
i) 2(-5x+3) + 7(3x-1)=0
j) 5(4x+3) + 2(x+6) = 3(x+8)
a) 4x+3=3x - 5 ;
b) -2x+7 = 3x-13
c) -3x+4=6x+5
d) 4-7x= -3x+1
e) 3 (x-8)=4x+5
f) -4(2+x) = 3x-5
g) 9(2-2x)= - (7x+1)
h) -3 (4+x) + 3x = 6(x+1)
i) 2(-5x+3) + 7(3x-1)=0
j) 5(4x+3) + 2(x+6) = 3(x+8)
1 Réponse
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1. Réponse maudmarine
a) 4x + 3 = 3x - 5
4x - 3x = -3 - 5
x = -8
b) -2x + 7 = 3x - 13
- 2x - 3x = - 7 - 13
-5x = -20
x = 20/5
x = 4
c) -3x + 4 = 6x + 5
-3x -6x = -4 + 5
-9x = 1
x = -1/9
x = -0,11
d) 4 - 7x = -3x + 1
4 - 1 = 7x - 3x
3 = 4x
4x = 3
x = 3/4
x = 0,75
e) 3 (x - 8) = 4x + 5
3x - 24 = 4x + 5
3x - 4x = 24 + 5
-x = 29
x = -29
f) -4(2 + x) = 3x - 5
-8 - 4x = 3x - 5
-4x - 3x = 8 - 5
-7x = 3
x = -3/7
x = -0,43
g) 9(2 - 2x) = - (7x + 1)
18 - 18x = -7x - 1
-18x + 7x = -18 - 1
-11x = -19
x = 19/11
x = 1,72
h) -3 (4 + x) + 3x = 6(x + 1)
-12 - 3x + 3x = 6x + 6
-3x + 3 - 6x = +12 + 6
-6x = -18
x = -18/6
x = -3
i) 2(-5x + 3) + 7(3x - 1) = 0
-10x + 6 + 21x - 7 = 0
-10x + 21x = - 6 + 7
11x = 1
x = 1/11
x = 0,09
j) 5(4x + 3) + 2(x + 6) = 3(x + 8)
20x + 15 + 2x +12 = 3x + 24
20x + 2x - 3x = -15 - 12 + 24
22x - 3x = - 27 + 24
19x = - 3
x = -3/19
x = - 0,157