lisanoce
May 13, 2009, 03:13 PM
How do you solve for x:
0.500 = x/(0.210 - x)(0.100)^2
I know it should be only one answer. Please explain how you got it thanks!
Zazonker
May 13, 2009, 08:19 PM
Are you sure you typed the problem correctly? It is relatively simple to solve, but it's a really ugly answer.
How to solve it? There's more than one way, but I would just do the multiplication in the denominator (right hand side), multiply the left hand side by the result, collect terms into the form ax = b. Divide and you'll have it.
Perito
May 13, 2009, 08:25 PM
0.500 = x/(0.210 - x)(0.100)^2
(0.100^2) \, \times \, 0.500 = x/(0.210 - x)
0.005 \, \times \, (0.210-x) = x
0.00105-0.005x = x
0.00105 = x + 0.005x = 1.005x
\frac {0.00105}{1.005} = x
0.001044776 \approx x
As Zazonker said, are you sure you wrote it down correctly. This looks pretty messy and that's not typical of a homework problem. On the other name, maybe the problem is this (I can't tell whether the 0.001^2 is in the numerator or denominator -- because of how you wrote it).
0.500 = \frac {x}{(0.210 - x)} \, \times \, (0.100)^2
But that's at least as messy.
50 = \frac {x}{(0.210 - x)}
10.5 - 50x = x
10.5 = 51x
\frac {10.5}{51} = x
0.20588 \approx x