a. 5/6+1/3*2
= 5/6+2/3
= 5/6+4/6
= 10/6
= 5/3
`a, 5/6 + 1/3 xx 2`
`= 5/6 + 2/3`
`= 5/6 + 4/6`
`=9/6`
`=3/2`
`b, 9/11 : (6/7 - 5/6)`
`= 9/11 : ( 36/42 - 35/42)`
`= 9/11 : 1/42`
`=9/11 xx42`
`=378/11`
b.9/11:(6/7-5/6)
= 9/11:(36/42-35/42)
= 9/11:1/42
= 9/11*42
= 378/11