22+23/K-1=22(K-1)+23/K-1=22k-22+23/k-1=22k+1/K-1就这么简单
22+23/(K-1)=22(K-1)/(K-1)+23/(K-1)=[22(K-1)+23]/(K-1)=(22K-22+23)/(K-1)=(22K+1)/(K-1)