That's not to say you don't run into problems along the way, but for me at least, solving those problems is where most of the fun is.My suggestion would be to start out reading two books:1 - Geometry2 - Algebra...and become very good at both.

Instead, figure out what the cap rate you thought you were buying at was, and do the algebra to back into a price that yields that same cap rate given what you now know about the rental situation.Make that your starting point for re-negotiations. 

Above history, algebra, and just about everything else.

You're talking calculus while I only understand algebra.

He also wanted me to enroll in the advanced math program (the school would be teaching ninth-grade algebra starting in seventh grade to those enrolled).

Here is an algebraic depiction of the formula used:For a property that was acquired after your most recent tax filing, so you have NOT had a chance to claim it on your most recent tax return, you can still use Net Rental Income from this property to help qualify as long as it is currently tenant-occupied (Note that many lenders have an overlay requiring documentation of at least 3 months of rent checks received).

Geometry and Algebra. 

Know your Algebra and Geometry, understand how to apply them, and you'll be successful. 

Geometry and Algebra

Basic algebra isn't up for debate.