Question

(3.1х+3.1)-(1.8х+1.8)=1.6х+1.6

Answer 1

(3,1x + 3,1) - (1,8x + 1,8) = 1,6x + 1,6 
3,1x+3,1-1,8x-1,8=1,6x+1,6
1,3x+1,3=1,6x+1,6
1,3x-1,6x=1,6-1,3
-0,3x=0,3
x=0,3:(-0,3)
x=-1