若3^x=6,9^y=2,求3^2x-4y+2的值
问题描述:
若3^x=6,9^y=2,求3^2x-4y+2的值
答
3^2x-4y+2
=(3^x)²÷(3^y)^4×3²
=36÷(9^y)²×9
=36÷4×9
=81