等差数列{an}中,am=ak+16,m-k=7,那么公差d=
问题描述:
等差数列{an}中,am=ak+16,m-k=7,那么公差d=
答
am=a1+(m-1)d ak=a1+(k-1)d两式相减得:am-ak=(m-k)d 由am=ak+16 m-k=7得d=16/7
等差数列{an}中,am=ak+16,m-k=7,那么公差d=
am=a1+(m-1)d ak=a1+(k-1)d两式相减得:am-ak=(m-k)d 由am=ak+16 m-k=7得d=16/7