[tex]bonjour\\\\\\3 x + 7 = 25 \\3 x = 25 - 7\\3 x = 18\\x = 6\\\\\\- 2 x + 5 x = 36\\3 x = 36\\\x = 12 \\\\\\\\14 = 5 x - 9\\\- 5 x = - 9 - 14\\- 5 x = - 23\\x = 23/5\\\\6 x - 4 = 3 x + 14 \\6 x - 3 x = 14 + 4\\3 x = 18\\x = 6 \\\\[/tex]
continue, tu as pas mal d'exemples
Bonjour,
Résoudre ces équations
a. 3x+ 7 = 25
3x + 7 - 7 = 25 - 7
3x = 18
3x/3 = 18/3
x = 6
b. -2x + 5x = 36
3x = 36
3x/3 = 36/3
x = 12
c. 14 = 5x–9
14 + 9 = 5x - 9 + 9
23 = 5x
5x = 23
5x/5 = 23/5
x = 23/5
d. 6x–4 = 3x+ 14
6x - 4 - 3x = 3x + 14 - 3x
3x - 4 = 14
3x - 4 + 4 = 14 + 4
3x = 18
3x/3 = 18/3
x = 6
e. 3x+ 5 = 5x+ 7
3x + 5 - 3x = 5x + 7 - 3x
5 = 2x + 7
5 - 7 = 2x + 7 - 7
-2 = 2x
2x = -2
2x/2 = -2/2
x = -1
f. 9 –2x= 11 + 4x
9 - 2x + 2x = 11 + 4x + 2x
9 = 11 + 6x
9 - 11 = 11 + 6x - 11
-2 = 6x
6x = -2
6x/6 = -2/6
x = -2/6
g. 3(x+ 5) = 32
3 × x + 3 × 5 = 32
3x + 15 = 32
3x + 15 - 15 = 32 - 15
3x = 17
3x/3 = 17/3
x = 17/3
h. 14 = 5(x–4)
14 = 5 × x + 5 × (-4)
14 = 5x - 20
14 + 20 = 5x - 20 + 20
34 = 5x
5x = 34
5x/5 = 34/5
x = 34/5
i. 7(x–2) + 3x–5 = -7
7 × x + 7 × (–2) + 3x - 5 = -7
7x - 14 + 3x - 5 = -7
10x - 19 = -7
10x - 19 + 19 = -7 + 19
10x = 12
10x/10 = 12/10
x = 12/10
j. 2(1 –2x) = 9 + 3x
2 × 1 + 2 × (–2x) = 9 + 3x
2 - 4x = 9 + 3x
2 - 4x - 3x = 9 + 3x - 3x
2 - 7x = 9
2 - 7x - 2 = 9 - 2
-7x = 7
-7x/-7 = 7/-7
x = -1
k. 10(x+ 4) + 7(2x–3) = 7
10 × x + 10 × 4 + 7 × 2x + 7 × (-3) = 7
10x + 40 + 14x - 21 = 7
24x + 19 = 7
24x + 19 - 19 = 7 - 19
24x = -12
24x/24 = -12/24
x = -12/24