定义一种新的运算"@"规定m@n=1\2m的2次方n的m-2次方,求【2@（-x）】@(3@x的二次方)

[2@（-x）]
=1/2×2²（-x)²-²
=1/8
(3@x²)
=1/2×3²(x²)³-²
=1/18x²
【2@（-x）】@(3@x的二次方)
=(1/8)@(1/18x²)
=1/2(1/8)²(1/18x²)^(1/8-2)
=32/(18x²)^(15/8)
=16/{27[(128×729)^(1/8)][x^(15/4)]}