-(+0.78)=-0.78

-(-0.78)=0.78

+(+0.78)=0.78

+(-0.78)=-0.78

-|+0.78|=-0.78

-|-0.78|=-0.78

+|+0.78|=0.78

+|-0.78|=-0.78

If you don't understand, please ask. . .