已知 a 1 = − 3 2 , a 2 = 5 5 , a 3 = − 7 10 , a 4 = 9 17 , a 5 = − 11 26 , … ,则 a 8 = .
()(3a﹣2b)=12a2b﹣8ab2.
计算3x(﹣2xy3)2=.
n为正整数,且x2n=3,则(3x3n)2的值为:.
﹣a2•(a2)2=.
计算:22005×0.52004=.