Hi Raj,
Sorry.. Monday I got called by my boss (I work from home usually) to work on a manual and had to bail. Yesterday, I had to go into work and solve a problem I couldn't solve from home. I left at 9:30 AM Tuesday (to work) and got home at 1:30 AM Wednesday. A 16 hour work day. Just got up two hours ago, for a call from work, then checked in here.
Again.. sorry I can't be on here as much as I like, but my job has my priority. But honestly, I would have solved such by plugging in a real number for A (given A=B) and worked it through and it would have failed somewhere along the procedure (step5?).
Anyway, I admittedly suck at Math. Now.. 45 years ago.. I was top of the class and aced Algebra. But I never use it in the real world. For the type of computer programming I do, Algebra is pretty rare. Even in Electronics it's rare.
Back in College this problem was submitted to the whole School. Given a month to work on it, I was the first to submit an answer Immediately. 60 people submitted answers over the next few weeks, including 10 professors. I was the only person with the correct answer.
Want to try it?

- Solve for RT
Years later, at a company that makes measuring equipment in electrically noisy environments, my Boss, with a PHD in Mathematics, submitted the ultimate algorithm using Linear Regression for filtering Noise from data gathered and digitized. He included a proof that it was unbeatable. It was a monster algorithm and took huge CPU and Memory Resources to run it.
I beat it with a statistical filter of my own design that took about 30 Bytes of Memory and about 20 lines of code, and run about 1000 times faster. He was furious.
But those were my glory days when I kicked butt against Experts in many fields. Today, I'm a has-been. My last Project (starting soon, before I can retire), requires me to do Voice Analysis and Speech Recognition. The Math on this one will be intense and insane. I have to do it on a small circuit board with a small CPU, little Memory, all self contained in a single stand-alone product. All my current Products Talk now, but this one has to Listen. I'm using a generic DSP. Needless to say.. it is scaring the crap out of me.. but I always succeed when I put my mind to a problem (so far.. lol).
A minor mention.. we have drifted radically from the OP.. so let's stop testing each other.. Ok?
I need to get back to my job on-hand shortly.. later my friend.
Best Regards,
Dave :^)