Réponse :
bjr
Explications étape par étape
ex 2
a)
3x - 5 = 3 +2x
3x-2x=3+5
x = 8
b)
2 - x = x +5
-x = x + 5 -2
-x = x +3
-3 = 2x
x = [tex]\frac{-3}{2}[/tex] = - 1,5
c)
6x + 7 = x -13
6x - x = -13-7
5x = -20
x = [tex]\frac{-20}{5}[/tex] = -4
d)
1+ x = -2x +4
x +2x = 4 - 1
3x = 3
[tex]\frac{3x}{3}[/tex]= [tex]\frac{3}{3}[/tex]
x = 1
ex 3
1. L'équation est : 3x - 4 = (x+3) ×( -2)
2.
3x - 4 = (x+3) ×( -2)
3x - 4 = (-2) × 3 + (-2) × x
3x - 4 = -2x -6
3x +2x = -6 + 4
5x = -2
[tex]\frac{5x}{5}[/tex] = [tex]\frac{-2}{5}[/tex]
x = -0,4
ex 4
a)
2(x+5) = 3(2x -2)
2×x + 2×5 = 3×2x + 3× (-2)
2x + 10 = 6x - 6
10 +6 = 6x - 2x
16 = 4x
4x = 16
[tex]\frac{4x}{4}[/tex] = [tex]\frac{16}{4}[/tex]
x = 4
b)
2(x-2) - 4(1-x) = 4
2×x + 2 × (-2) - 4 × 1 -4 × (-x) = 4
2x - 4 -4 + 4x = 4
6x - 8 = 4
6x = 4 + 8
6x = 12
x = 2
c)
3(x-2) + 4 = 2 - x
3×x + 3 × (-2) +4 = 2 -x
3x -6 +4 = 2-x
3x-2 = 2-x
3x + x = 2+2
4x = 4
x = 1
d)
5(x + 1) = 3(3-x)
5×x + 5×1 = 3×3 + 3×(-x)
5x + 5 = 9 - 3x
5x + 3x = 9-5
8x = 4
x = 0,5
bonne continuation
