已知数列{An}中,A1=1,A2=5/3,A(n+2)=5/3A(n+1)-2/3An,Bn=A(n+1)-An,证明

A(n+2)=A(n+1)+2/3[A(n+1)-An]
[A(n+2)-A(n+1)]/[A(n+1)-An]=2/3
B(n+1)=A(n+2)-A(n+1)
Bn=A(n+1)-An
代入：
B(n+1)/Bn=2/3
{Bn}为等比数列,公差为2/3