已知9n+32n-1=8,求(33n)2-6×92n的值.

问题描述:

已知9n+32n-1=8,求(33n2-6×92n的值.

∵9n+32n-1=8,
∴32n+32n

1
3
=8,
∴32n(1+
1
3
)=8,
∴32n=6,
∴(33n2-6×92n=(32n3-6×(32n2=63-6×62=0.