log2(2x-3)=log2(2(x-3/2))
=log2(2)+log2(x-3/2)
=1+log2(x-3/2)
设向量a=(m,n)
y=log2(x)+1按照a平移后,得到：y=log2(x-m)+1+n
即得到：y=log2(x-3/2)+5
故：m=3/2,n+1=5
故：a=(3/2,4)