One doesn't have to have a science degree with years of advanced mathematics, or an economics hobby, or more than an 8th grade education. 

If you have modest retirement savings, and are in your highest earning years - taking the tax deduction today is going to work out the best mathematically - you can take the money off the top today when your income is high, and pull the money out later at near-zero tax rates when you are trying to live off a too-small 401k.If you are young and in a low tax bracket, the Roth is golden, you are missing out on a known small tax savings for the long term benefit of not having to worry about income tax policy.

I even disagree with my friend @Ned Carey, which is the first time that happened...In mathematical terms, I would tell you to underwrite to IRR.

Does anyone have any recommendations on books, blogs, or any other resources that can help with truly understanding the financing/mathematics behinds deals? 

I taught Chemistry and Mathematics for 10 years in Brooklyn and Philly and then decided to give that all up for a change of career.

No i just need the mathematical formulas i need to understand thats it

😬you're asking what the mathematically efficient answer is to a question that you don't want the mathematically correct answer to.to find the best answer given your parameters, you would need to know which has the worst ROI.

Those are a lot of expenses to be covered by the relatively low amount left over and still have $400/mo in your pocket.Is it mathematically impossible?

I've just yet to see anything like it in my area and am curious if it is just unrealistic in the current environment or if people out there are finding opportunities that mathematically make sense and I just need to find the Michael Jordan of real estate agents haha.Thank you again for your help and input!

Here is the mathematical equation:Assets x ROI = Cashflow > Expense BudgetHere are the steps:Determine you annual Expense Budget based on how you want to live.Example: $75K/yearDetermine your Return on Investment based on your Risk Tolerance.Your Risk Tolerance is based on how wiling are you to risk losing it all when it comes to your incoming producing properties to where you would have to go back to work.Use a scale of 1-100, 1 = cash in mattress and 100 = I'm gambling the rent money a the craps table.Take your Risk Tolerance # and divide by 5 to calculate your ROI.Example: Risk Tolerance = 50, ROI = 50/5 = 10%Income Producing Assets = Expense Budget/ROIExample: $75K/10% = $750K in income producing assetsFor real estate, Income Producing Assets = Property Equity, not the market value of the property.