Thread: How to simplify this log problem

I am asked to simply this formula:

d = ln(45)-ln(35) / ln(81) - ln(49)

Using the laws of logarithms I am supposed to simplify this expression and show that d = 1/2

I can see that d = ln(45/35)/ln(81/49) but not sure how that helps.

Can anyone give me a clue?

Originally Posted by angypangy

I am asked to simply this formula:

d = ln(45)-ln(35) / ln(81) - ln(49)

Using the laws of logarithms I am supposed to simplify this expression and show that d = 1/2

I can see that d = ln(45/35)/ln(81/49) but not sure how that helps.

Can anyone give me a clue?

Good start. Now a couple of hints for you:



and



Does that help?

If it were 7/9 / 9^2/7^2 - then it cancels down to 7/9. But this is ln(7/9 / 9^2/7^2) - so can I do it the same way? Does it just become ln(7/9)?

?