Question

log(2)9×log(3)4

Answer 1

log(2)9 = 2log(2)3
log(3)4= 2log(3)2
=》4log(2)3 *log(3)2
=> 4* (log(2)3*(1/(log(2)3)) )=4
//由换底公式 log(a)(b)=log(b)(b)/log(b)(a) ----取以b为底的对数,log(b)(b)=1  =1/log(b)(a)

追问

谢谢咯

太给力了，你的回答完美解决了我的问题！

Answer 2

=(lg9/lg2) * (lg4/lg3)= (lg3^2/lg2) * (lg2^2/lg3)=(2lg3/lg2） * （2lg2/lg3）=2*2=4
注：3^2代表3的2次方

Answer 3

=log(2)4*log(3)9=2*2=4

Answer 4

=lg9/lg2×lg4/lg3
=2lg3/lg2×2lg2/lg3
=4

Answer 5

6