1/3+1/3÷5/6
=1/3+1/3*6/5
=1/3(1+6/5)
=1/3*11/5
=11/15
1/4÷（6-4/13-9/13）
=1/4÷[6-(4/13+9/13）]
=1/4÷(6-1)
=1/4÷5
=1/4*1/5
=1/20
（3/8+5/6+50%）÷3/4
= （3/8+5/6+1/2）*4/3
=3/8*4/3+5/6*4/3+1/2*4/3
=1/2+10/9+2/3
=1/2+(10+6)/9
=1/2+16/9
=(9+32)/9
=41/9