若3^n+1*5^n+1=15^2n-7,则n=多少
问题描述:
若3^n+1*5^n+1=15^2n-7,则n=多少
答
3^n+1*5^n+1=15^2n-7
15^(n+1)=15^(2n-7)
n+1=2n-7
n=8.