I am sure of what I heard on television a few years ago.
You misunderstood, or recalled incorrectly, as...
He claimed to have a new equation which proves all matter can be converted back into energy.
...he clearly didn't claim that, because if he had...
It is because I wanted to see this equation that I e-mailed his web site.
...then he (or the assistant) would have responded in the affirmative.
See how that works?
You write: "Hey. Professor Hawking, on television a few years back, you said you had an equation which will convert matter back into energy.
To which, if he had made such a claim, he (assistant) would have responded with: "Why, yes, I did! What an outstanding memory you have, my good man! Here ya go..."
Or something along those lines. That's how Q&A works. You ask the question, and if the guy actually made the claim, he responds in the affirmative. If he didn't actually make the claim, he responds in the negative, which he did.
As for his book, he says on page 1.
" Someone told me that each equation I included in the book would halve the sales, I therfore resolved not to have any equations at all. In the end, however, I did put the one equation, Einstein's famous E = mc2. I hope that will not scare off half my readers"
So the evil professor deliberately withheld all equations from his book just to flummox you? What is your point?