Sagot :
Bonsoir,
c)
4x - 1 = 5x + 3
<=> 4x - 1 - 3 - 4x = 5x + 3 - 3 - 4x
<=> -4 = x
<=> x = -4
d)
2/5 - 1/2x = - x - 2
<=> 2/5 - 1/2x + 1/2x + 2 = - x - 2 + 1/2x + 2
<=> 2/5 + 10/5 = -2/2 x + 1/2x
<=> 12/5 = - 1/2 x
<=> 12/5 * (-2) = -1/2 x * (-2)
<=> - 24/5 = x
<=> x = -24/5
Bonne soirée,
Thomas
Réponse :
c) 4x - 1 = 5x + 3
4x - 1 - 3 = 5x + 3 - 3
4x - 4 = 5x
4x - 4x - 4 = 5x - 4x
- 4 = x
d) 2/5 - 1/2x = -x - 2
2/5 - 2/5 - 1/2x = -x - 2 - 2/5
-1/2x = -x - 12/5
-1/2x + x = -x + x - 12/5
1/2x = -12/5
2*(1/2x) = 2*(-12/5)
x = -24/5
* = signe "multiplié"
j'espère t'avoir aidé !