Sagot :
Hello,
Je te montre
4x + 5 = 6x + 2
4x - 6x = 2 - 5
-2x = -3
x = 3/2 = 1.5
Vérification :
4 * 1.5 + 5 = 11
6 * 1.5 + 2 = 11
Comme les deux expressions donnent le même résultat avec 2, la solution est vérifiée.
7x + 10 = 4x + 25
7x - 4x = 25 - 10
3x = 15
x = 15/3 = 5
5x - 2 = 2x + 7
5x - 2x = 7 + 2
3x = 9
x = 9/3 = 3
4x - 5 = 11x + 2
4x - 11x = 2 + 5
-7x = 7
x = 7/-7 = -1
à toi de continuer ;)
Bonjour,
- 4x + 5 = 6x + 2
4x + 5 - 4x = 6x + 2 - 4x
5 = 2x + 2
5 - 2 = 2x + 2 - 2
3 = 2x
2x/2 = 3/2
x = 1,5
Vérification : 4(1,5) + 5 = 6 + 5 = 11
6(1,5) + 2 = 9 + 2 = 11
Donc x = 1,5
- 7x + 10 = 4x + 25
7x - 4x = 25 - 10
3x = 15
3x/3 = 15/3
x = 5
Vérification : 7(5) + 10 = 35 + 10 = 45
4(5) + 25 = 20 + 25 = 45
Donc x = 5
- 5x - 2 = 2x + 7
5x - 2 + 2 = 2x + 7 + 2
5x = 2x + 9
5x - 2x = 2x + 9 - 2x
3x = 9
x = 9/3
x = 3
Vérification : 5(3) - 2 = 15 - 2 = 13
2(3) + 7 = 6 + 7 = 13
- 4x - 5 = 11x + 2
4x - 5 - 4x = 11x + 2 - 4x
-5 = 7x + 2
-5 - 2 = 7x + 2 - 2
-7 = 7x
7x/7 = -7/7
x = -1
Vérification : 4(-1) - 5 = -4 - 5 = -9
11(-1) + 2 = -11 + 2 = -9
- 5x - 7 = 8x + 13
5x - 7 - 5x = 8x + 13 - 5x
-7 = 3x + 13
-7 - 13 = 3x + 13 - 13
-20 = 3x
3x/3 = -20/3
x = -20/3
Vérification : 5(-20/3) - 7 = -100/3 - 21/3 = -121/3
8(-20/3) + 13 = -160/3 + 39/3 = -121/3
- 14 - 2x = 3x - 36
14 - 2x + 2x = 3x- 36 + 2x
14 = 5x - 36
14 + 36 = 5x - 36 + 36
50 = 5x
5x/5 = 50/5
x = 10
Vérification : 14 - 2(10) = 14 - 20 = -6
3(10) - 36 = 30 - 36 = -6