Logarithm and logarithm operation, help calculate thank you ㏒ 2 ^ 3 = a, ㏒ 3 ^ 7 = B, use a, B to represent ㏒ 42 ^ 56 (2 ^ 3 is the cubic power of 2)

Logarithm and logarithm operation, help calculate thank you ㏒ 2 ^ 3 = a, ㏒ 3 ^ 7 = B, use a, B to represent ㏒ 42 ^ 56 (2 ^ 3 is the cubic power of 2)

∵log3=a,∴log2=1/a.
∴log56
=[3log2+log7]/[1+log2+log7]
=[3/a+b]/[1+1/a+b]
=(3+ab)/(1+a+ab).

Logarithm operation is very slow, how to do
How to improve the computing speed?

Starting from the simple topics in the textbook, practice a few times a day, and it's easy to do after a long time. The key is to do, persist in doing, and everything will become very simple. The truth is understood, and the key is to put it into action

Help to teach how to calculate this topic, the operation of logarithm
log2(47×25)
=7log2 4+5log2 2
The next step won't count. The 4 and 2 after the space are logarithms
Here's another one:
M=1g20-lg0.001
=1g 20000
Not next
Please explain. I am rather stupid, I can't understand many times
log2(47×25)
=7log2 4+5log2 2
=7*2log2 2+5log2 2
=7*2*1+5*1
=19
M=1g20-lg0.001
=1g 20000
lg(2*10000)
=lg2+lg10000
=4+lg2
_______________
I don't understand why I have to do this

log2(47×25)
=7log2 4+5log2 2
=7*2log2 2+5log2 2
=7*2*1+5*1
=19
M=1g20-lg0.001
=1g 20000
lg(2*10000)
=lg2+lg10000
=4+lg2

How to multiply two logarithms of the same base

log(a)(b)=1/log(b)(a)log(a)(N)=log(b)(N)÷log(b)(a)1、a^(log(a)(b))=b 　　2、log(a)(a^b)=b　　3、log(a)(MN)=log(a)(M)+log(a)(N); 　　4、log(a)(M÷N)=log(a)(M)-log(a)(N); 　　5、log(a)(M^n)=nlog(a)(M) ...

How to multiply or divide two logarithms with the same base
For example, is there any formula for logam * Logan?

There is no formula for logam * Logan
There is no formula for logam △ Logan,
The formula is logam + Logan = loga (MN)
And logam Logan = loga (M / N)