If a*b=2a+3b for all a and b, then what is the value of 4*3$

I see... the * isn't multiplication....

It would have been far clearer if you had either stated that up front or used a different symbol.

If a*b=2a+3b for all a and b, then what is the value of 4*3

\(\begin{array}{|rcll|} \hline 4*3 &=& 2\cdot 4 + 3\cdot 3 \\ &=& 8+9 \\ &=& \mathbf{17} \\ \hline \end{array}\)