{0.85-[12+4*(3-10)]}/5
={0.85-[12+4*(-7)]}/5
={0.85-[12-28]}/5
={0.85-[-16]}/5
=16.85/5
=3.37
(27/20-8/15)/(0.2-6.8)
=(81/60-32/60)/(-6.6)
=(49/60)/(-33/5)
=-49/396
2+(1+2/5-1/3)
=2+(7/5-1/3)
=2+(21/15-5/15)
=2+16/15
=46/15