Bài 5 : Tính nhanh :
a, A =\(1993^{1^{2\times3\times4\times.....\times1994}}\)
b, B = \(1994^{\left(225-1^2\right)\times\left(225-2^2\right)\times....\times\left(225-50^2\right)}\)
c, C =\(\frac{2^{10}\times3^{31}+2^{40}\times3^6}{2^{11}\times3^{31}+2^{41}\times3^6}\)
d, D = \(\left(1+2+2^2+2^3+.....+2^{2003}+2^{2004}\right)-2^{2005}\)