Modeling with first order linear differential equations

[DODGEVIPER13]

Homework Statement

uploaded file (Problem 5)

Homework Equations

uploaded file

The Attempt at a Solution

Ok so I think I have the correct answer but the problem is I don't know how to solve for the actual answer with 2 equations which one do I plug into? Sorry for all the erasing!

 

[DODGEVIPER13]

Oh an the 1400000 is suppose to be there sorry it is so light and I solved the t = 71.7994 using wolfram.

 

[DODGEVIPER13]

Uggg no replies, I guess my problem was too long or something?

 

[DODGEVIPER13]

Can someone please help me out I don't think it is too outrageous I have already done the work it is quite literally just plugging and playing from here my question simply is first did I get the set up right and if I did then what do I plug in at the end?