• Apr 1st 2008, 07:53 PM
hjco88
how to solve for X???

.0158 / [.184^4] * X = 5.6e^11

much thanks!
• Apr 1st 2008, 07:55 PM
Jhevon
Quote:

Originally Posted by hjco88
how to solve for X???

.0158 / [.184^4] * X = 5.6e^11

much thanks!

there are several ways the left hand side of your equation can be interpreted, please clarify!

is it $\displaystyle \frac {0.0158}{0.184^4}x$ or $\displaystyle \frac {0.0158}{0.184^4x}$ ??
• Apr 1st 2008, 07:58 PM
hjco88
the 2nd one...
\frac {0.0158}{0.184^4x}

its the second one :o)
thanks so much! you are saving my night hahaha
• Apr 1st 2008, 08:05 PM
Jhevon
Quote:

Originally Posted by hjco88
\frac {0.0158}{0.184^4x}

its the second one :o)
thanks so much! you are saving my night hahaha

ok, one way to go is to flip both sides. but students usually have trouble reconciling with that, so let's not do that. students seem to like cross multiplying, so let's do that one. you know how to cross multiply right?

$\displaystyle \frac {0.0158}{0.184^4x} = \frac {5.6e^{11}}1$

cross-multiply means we multiply the numerator on the right by the denominator on the left and the numerator on the left by the denominator on the right.

which means, we multiply the blues and the reds together:

$\displaystyle \frac {{\color{red}0.0158}}{{\color{blue}0.184^4x}} = \frac {{\color{blue}5.6e^{11}}}{\color{red}1}$

so we get:

$\displaystyle 5.6e^{11} \cdot 0.184^4x = 0.0158$ ...........now divide both sides by $\displaystyle 5.6e^{11} \cdot 0.184^4$

$\displaystyle \Rightarrow x = \frac {0.0158}{5.6e^{11} \cdot 0.184^4}$

now plug that into your calculator and simplify. you could have as well work some of these out from the beginning if it is easier for you
• Apr 1st 2008, 08:08 PM
hjco88
ah!
you are a lifesaver!!!! thank you so so much, you have no idea. have a lovely rest of your evening! :o)
• Apr 1st 2008, 08:09 PM
Jhevon
Quote:

Originally Posted by hjco88
you are a lifesaver!!!! thank you so so much, you have no idea. have a lovely rest of your evening! :o)

it's 12:10pm, it's morning now.

but anyway, take care and good luck
• Apr 1st 2008, 08:10 PM
hjco88
ur a funny one hah! well thank you nonetheless, and you take care as well
:)