2的m次方=3,4的n次方=5求2的2m次方减6n+1的值61og4(5)是什么啊

Question

2的m次方=3,4的n次方=5求2的2m次方减6n+1的值
61og4(5)是什么啊

Answer 1

2^m=3,4^m=5,两边取对数得,
m=log(2)3,(注:以2为底,3的对数,下同).
n=[log(2)5]/2,
2^(2m-6n+1)
=(2^2m)*2/[2^(6n)]
=9*2/5^3
=18/125.