Thursday

April 24, 2014

April 24, 2014

Posted by **Michael Weston** on Sunday, November 21, 2010 at 10:33pm.

log10(8 x) − log10(1 + √x) = 2

for x.

- Math -
**Michael Weston**, Sunday, November 21, 2010 at 10:40pmthe 10s were supposed to be subscripts so just ignore them

- Math -
**MathMate**, Sunday, November 21, 2010 at 10:58pmIf the 10's are subscripts, they are meant to be the base of the log, and are important.

log_{10}(8 x) − log_{10}(1 + √x) = 2

log_{10}(8x/(1+√x)) = 2

Take anti-log (or raise to power of 10)

8x/(1+√x) = 10²

8x=100(1+√x)

If you plot the graph 8x-100(1+√(x)), you will find a minimum of about -400 at x=40, and a zero at about x=180.4.

- Math -
**Reiny**, Sunday, November 21, 2010 at 10:59pmlog( 8x/(1+√x) = 2

8x/(1+√x) = 100

8x = 100 + 100√x

8x - 100 = 100√x

square both sides

64x^2 - 1600x + 10000 = 10000x

64x^2 - 11600x + 10 000 = 0

x = (11600 ± √132000000)/128

= 180.384 or .8662

since we squared we must check the answer

1. x = 180.384

LS = 2

RS = 2

2. x = .8662

LS = .555 ≠ RS

so x = 180.384

**Related Questions**

Algebra 2 - If log10^9=0.95 and log10^2=0.30, find the following: 1. log10^9/2 2...

Logarithms - Using the approximation log10^2=0.301, find: log10^8

Pre Calculs - The pH of a chemical solution is given by the formula pH = -log10...

Math - I can't calculate 1 as the answer given to the following problem. I keep ...

phyiscs repost 2 - Calculate the sound level in decibels of a sound wave that ...

Math - How do I express these in scientific notation AND Log10 form? 1) ln(8.1) ...

Algebra 2 - Express as a logarithm of a single number or expression: 1. 5log4^p+...

chemistry. am i doing this right? - 1.) One of the trials in this week's ...

math - The number 27+200−−−√−−−−...

math - how can you simplify this?? log10(10^.5) log10 as in log base 10 By ...