若3的2n加1次方加3的2n等于324 求N

问题描述:

若3的2n加1次方加3的2n等于324 求N

3^(2n+1)+3^(2n)
=3^(2n)[3+1]
=4×3^(2n)=324
=>3^(2n)=81
=>2n=4
=>n=2