Tính gía trị biểu thức sau

tính :

1. ( 9/10 -15/16) . ( 5/12 - 11/15 -7/20)
2. [ -3/2 + 4 . 2 ,5 - ( 3. 7/6)^2 ] . ( -3/2)^2
3. -1/15 ^3 + (-2/3) ^2 : 8/3 - 5/6 
4. (-1/5)^2 + 1/5 -2.(-1/2)^3 -1/2 
5. 4 - 1 + (1/3)^4 .3^6
6. -6.(-2/3) .0,25
7. -15/4. -7/15. -12/5
8. 5/8 + 9/4 . 5/3 - 1/4 .5/6 
9. (-11/2). (-1/2 ) - 2/3  .(-2/3)