Question

如果log2-

3

1-4x

9

=0，則x=

-2

．

Answer 1

分析：對(duì)數(shù)的特殊性質(zhì)：對(duì)任意不等于1的正數(shù)a，都有l(wèi)og_a1=0．由此可得真數(shù)

1-4x

9

為1，解之即得實(shí)數(shù)x的值．

解答：解：∵對(duì)任意不等于1的正數(shù)a，都有l(wèi)og_a1=0
∴由log2-

3

1-4x

9

=0，得

1-4x

9

=1，解之得x=-2
故答案為：-2

點(diǎn)評(píng)：本題給出對(duì)數(shù)值，求對(duì)數(shù)的真數(shù)中的x值，著重考查了對(duì)數(shù)定義與性質(zhì)等基本運(yùn)算，屬于基礎(chǔ)題．