Sagot :

eva189
4x-7=21
4x=21+7
4x= 28
X = 28/4 =7

-2x +6 =123
-2x =123-6
-2x =117
X =117/-2 =-58.5

9x+11 = -16
9x =-16-11
9x = -27
X= -27/9 =-3

-5x +40 =72
-5x =72-40
-5x=32
X= 32/-5 =-6,4