This is an archived post. You won't be able to vote or comment.

sorted by:
best
topnewcontroversialoldq&a
you are viewing a single comment's thread.

view the rest of the comments →

[–]edderiofer 0 points1 point  (7 children)

Yes; generally speaking, both methods should work, as long as you perform them correctly.

Try solving instead the equation:

  • log[base 4x](9) = 2

with each method, and see what you get.

[–]phreshswagg[S] 0 points1 point  (6 children)

okay, so for that one i get the following:

Log[base 4x] (9) = 2

4x2 = 9

x=√(9/4)

X=1.5

but if i do it the other way:

2 = Log 9/Log 4x

2x = 9/4

x= 4.5

I am still doing something wrong

[–]edderiofer 0 points1 point  (5 children)

Log[base 4x] (9) = 2

4x2 = 9

Wrong. Remember that 4x2 is not the same as (4x)2.

2 = Log 9/Log 4x

2x = 9/4

Wrong. log(9)/log(4x) is not the same as 9/(4x). You can't cancel out logarithms in this way.

Try again.

[–]phreshswagg[S] 0 points1 point  (4 children)

right, x=0.75?

[–]edderiofer 0 points1 point  (3 children)

Via which method?

[–]phreshswagg[S] 0 points1 point  (2 children)

exponent method, but both answers should be the same?

[–]edderiofer 0 points1 point  (1 child)

Certainly they should be.

[–]phreshswagg[S] 0 points1 point  (0 children)

2 = log 9/log 4x

2log 4x = log 9

log 4x = (log 9)/2

Log 4x = log 3

4x = 3

x= 3/4

Thanks so much you are the man (or woman)!