1-1,7x-0.8x-2=3.4 -2.5x=4.4 x=-1.76
1-1.7x-(0.8x+2)=3.4 1-1.7x-0.8x-2=3.4 -1.7x-0.8x=3.4-1+2 -2.5x=4.4 -x=4.4/2.5 x=-1.76