The problem can be found here:
http://img229.imageshack.us/img229/3647/q26ry7.jpg
I'm guessing that it is in the second line of the solution. Not sure how would I express this big boy as a single log?
Thanks!
2007-11-22 12:27:07 · 7 answers · asked by ms_lotr_freak 3 in Science & Mathematics ➔ Mathematics
1/2log16 ≠ log(16/2) On the second line.
Also there is a mistake on the 4th line. -log(4/5) should become ÷ 4/5)
To answer this correctly:
2log5 - log(4/5) +1/2log(16)
= log5² - log(4/5) + log(16^(1/2))
= log25 -log0.8 + log4
=log25×4 ÷ 0.8)
=log125
2007-11-22 12:30:22 · answer #1 · answered by Anonymous · 4⤊ 0⤋
Yes there is a mistake in line two of the solution
Half of the log of a number is equal to the log of the squareroot of the number.
2*log2(5)-log2(4/5)+1/2*log2(16)
4*4=16 so 4 is the square root of 16
log2(25)-log2(4/5)+log2(4)
log2(25/(4/5)*4)
log2(25*5/4*4)
log2(125)
log2(2)=1
log2(4)=2
log2(8)=3
log2(16)=4
log2(32)=5
log2(64)=6
log2(128)=7
log2(125) would be between 6 and 7 and much closer to 7 than to 6
2007-11-22 12:45:04 · answer #2 · answered by anonimous 6 · 0⤊ 0⤋
Hey there!
The fourth line contains the error. Instead of dividing 25 by 4/5, it was the product of 25 and 4/5. Also he made a mistake in the second line. It should be 16^1/4.
Here's the correct answer.
2log(base 2)(5)-log(base 2)(4/5)+1/2*log(base 2)(16) -->
log(base 2)(5^2)-log(base 2)(4/5)+log(base 2)(16^1/2) -->
log(base 2)(25)-log(base 2)(4/5)+log(base 2)(4) -->
log(base 2)(25*5/4*4) -->
log(base 2)(125)
So the correct answer is log(base 2)(125).
Hope it helps!
2007-11-22 12:36:42 · answer #3 · answered by ? 6 · 0⤊ 0⤋
1/2log16 â log(16/2) the 2nd line
2007-11-22 12:42:58 · answer #4 · answered by Anonymous · 0⤊ 0⤋
2log(2)5 - log(2)(4/5) + (1/2)log(2)16
log(2)(5^2) - log(2)(4/5) + log(2)(16^(1/2))
log(2)25 - log(2)(4/5) + log(2)4
log(2)((25 * 4)/(4/5))
log(2)(100/(4/5))
log(2)(500/4)
log(2)125
log(2)(5^3)
ANS : 3log(2)5
you forgot, thats -log(2)(4/5) not +log(2)(4/5) so your dividing the log(2)(25) and log(2)4 by log(2)(4/5)
2007-11-22 13:40:44 · answer #5 · answered by Sherman81 6 · 0⤊ 0⤋
2 log2 5 - log2 (4/5) + (1/2) log2 16
log2 5² - log2 (4/5) + log2 16^(1/2)----Error line
log2 25 - log2 (4/5) + log2 4
log2 100 - log2 (4/5)
log2 100 / (4/5)
log2 125
2007-11-22 22:31:34 · answer #6 · answered by Como 7 · 0⤊ 1⤋
the second line
1/2logbase2 is not equal to logbase2of 16/2
2007-11-22 12:33:26 · answer #7 · answered by southerngal102192 2 · 0⤊ 0⤋