`\text{a)}`
` [ 6 . (-1/3)^2 - 3^2 . (-1/3) +1 ] : (-1/3 - 1)`
`= [ 6 . 1/9 - 9 . 2/3] : (-4/3)`
`= [ 6/9 - 18/3] : (-4/3)`
`= [ 6/9 - 54/9] : (-4/3)`
`= -16/3 . 3/-4`
`= -16/-4`
`= 4`
`\text{b)}`
`\frac{(2/3)^3 . (-3/4)^2 . (-1)^2003}{ (2/5)^2 . (-5/2)^3}`
`= 6/9 . -9/16 : 4/25 . (-125/8)`
`= 3/-4 : -5/ 2`
`= -3/4 . 2/-5`
`= 9/20`