-(2,5x - 2.5) - (3.1x - 3.1)= - (1.6 - 1.6x)
-2,5x + 2.5 - 3.1x + 3.1= - 1.6 + 1.6x
-2,5x- 3.1x-1.6x = - 1.6-3.1-2.5
-7.2x = -7.2
x = 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
3.1x-1.8x-1.6x = 1.6 - 3.1+1.8
-0.3x = 0.3
x=-1