划成分数然后约分就行了-27x4/9x4/9x(-1/24)=-12x4/9x(-1/24)=16/3x1/24=2/9
-27÷9/4×4/9÷(-24)=-27÷(9/4×4/9)÷(-24)=-27÷1÷(-24)=27÷24=9/8
-27/(9/4)*4/9/(-24)=27*4/9*4/9*1/24=27*4*4*1/9*9*24=2/3
9/8 2又1/4×4/9=1