3.86-19/2+6.14-19/17
=3.86+6.14-19/2-19/17
=10-(9+1/2)-(1+2/17)
=10-9-1-1/2-2/17
= -(1/2+2/17)
= -(17/34+4/34)
= -21/34对不起啊,分数打错了.是19分之2和19分之173.86-2/19+6.14-17/19=3.86+6.14-2/19-17/17=10-(2/19+17/19)=10-19/19=10-1=9