A tank initially contains 200 gal of fresh water with 0 lbs of salt. Brine whose salt concentration is 2lb/gal flow in at 2 gal/min and the mix flows out at the same rate.(adsbygoogle = window.adsbygoogle || []).push({});

x = salt content, t = time.

So I figure that dx = 4dt - 2xdt/200 or dx = (400 - x).01dt

dx/(400-x) = .01dt

[tex]\int_{0}^{x}[/tex] [tex]\frac{dx}{400-x}[/tex]] = [tex]\int_{0}^{100}[/tex]^{100}_{0}.01dt

ln([tex]\frac{400-x}{400}[/tex] = 1

400 - x = 400e

x = 400-400e

which obviously isn't correct.

Can somebody show me what I'm doing wrong here?

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# ODE dilution problem

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