;(2^-1)^x=1/2*4^-1*1/8*16^-1*1/32*64^-1
(2^-1)^x=1/2*1/4*1/8*1/16*1/32*1/64
(1/2)^x=(1/2)^(1+2+3+4+5+6)
(1/2)^x=(1/2)^21
X=21
1/2*4^-1*1/8*16^-1*1/32*64^-1
=(1/2)*(1/4)*(1/8)*(1/16)*(1/32)*(1/64)
=(1/2)^1*(1/2)^2*(1/2)^3*(1/2)^4*(1/2)^5*(1/2)^6
=(1/2)^(1+2+3+4+5+6)
=(1/2)^21
=(1/2)^x
x=21