By means of a truth table. Prove that A*B =A + B?

Answer 1

But... it isn't. I assume, from your reference to truth tables, that you're referring to boolean algebra, so you're asking me to show that A and B = A xor B. It isn't. In fact , A * B implies ¬A+B, and vice versa.

Edit: Um... dualspace, what about A=5/4 and B=5? Or A=2 and B=2? Or in general:
ab=a+b
(b-1)a=b
a=b/(b-1)
Although, as mentioned above, that's not what he's talking about.

Answer 2

0*0=0
0+0=0

Answer 3

We'd need to know the values of A and B to do this, and the only values that make it true are if A=0 and B=0.