Question

1)12-4(x-3)=39-9x
2)2(3x+5)-3(4x-1)=11,8

Answer 1

12 - 4*(x-3) = 39 - 9x
12 - 4x + 12 = 39 - 9x
24 - 4x = 39 - 9x 
-4x + 9x  = 39 - 24
5x = 15
x= 3
==========
2 * (3x+ 5 ) - 3*(4x-1) = 11.8
6x + 10 - 12x + 3 = 11.8
-6x + 13 = 11.8
-6x = 11.8 - 13
-6x = -1.2
x = 0.2 

Answer 2

1)
12-4(x-3)=39-9x
12-4x+12=39-9x
-4x+9x=39-12-12
5x=15
x=15:5
x=3
====
2)
2(3x+5)-3(4x-1)=11,8
6x+10-12x+3=11,8
-6x+13=11,8
6x=13-11,8
6x=1,2
x=1,2:6
x=0,2