(1/4+1/2-1/3)÷5/6
=(1/4+1/2-1/3)×6/5
=1/4×6/5+1/2×6/5-1/3×6/5
=3/10+3/5-2/5
=3/10+(3/5-2/5)
=3/10+1/5
=1/2