2的n+4次方-2(2n)除于2(2的n+2次方)

(2^n+4-2^2n)/2(2^n+2)
=(2^n×2^4-2^n×2^n)/2^n×2^3
=(2^4-2^n)/2^3
=2-2^n-3

如果是2乘以2N ^为次方 x为乘以
(2^[n+4]-2X2n)/{2(2^[n+2])}

=(2^[n+4]-2X2n)/{2^[N+3]}

=2^[n+4]/{2^[N+3]}-4n/{2^[N+3]}

=2^[N+4-n-3]-（N/{2^[N+1]}）

=2-(n/{2^[N+1]})

题目出的不清不楚

2