Sagot :
a. 3x +7 = 11
3x = 11 - 7
3x = 4
x = 3/4 = 1,3
b. 4x - 12 = x
4x - x = 12
3x = 12
x = 4
c. 3x + 11 = 4x - 12
3x - 4x = - 12 - 11
- x = - 23
x = 23
Réponse :
a) 3x+7=11
3x= 11-7
3x= 4
x= 4/3
b) 4x-12 = x
4x+x=12
5x= 12
x= 12/5
c) 3x+11 = 4x-12
3x -4x = -12-11
-x= -23
x= 23
d) 6-11 = 9x+15
-9x= 15-6+11
-9x = 20
x= [tex]\frac{20}{-9}[/tex]
e) -3x+11 = 4x -17
-3x-4x = -17-11
-7x = -29
x= -27/ -7
x= 27/7
f) -2x-11 = -3x+13
-2x+3x= 13+ 11
x= 24
g) 5-4x = -3x
-4x+3x = -5
-x = -5
x= 5
h) 4x +7 = 2x+7
4x-2x= 7-7
2x = 0
x= 0
i) 3x -11 = 3x +17
3x-3x = 17-11
16