0.45^3-1.45^3-0.45*1.45=(0.45-1.45)*(0.45^2+0.45*1.45+1.45^2)-0.45*1.45=-0.45^2-2*0.45*1.45-1.45^2=-(0.45^2+2*0.45*1.45+1.45^2)=-(0.45+1.45)^2=-1.9^2=-3.61
0.507^3+0.493^3-0.507*0.493=(0.507+0.493)(0.507^2--0.507*0.493+0.493^2)- 0.507*0.493= 0.507^2-2*0.507*0.493+0.493^2=(0.507-0.493)^2=0.014^2=0.000196