### Instruction: Define the operation $\S$ as follows: $a\,\S\, b=3a+5b$. What is the value of $7\,\S\,2$?### Response: To apply the operation $\S$ to 7 and 2, I need to plug in 7 for $a$ and 2 for $b$ in the formula $3a+5b$.
So, $7\,\S\,2=3(7)+5(2)$.
I can simplify this by multiplying 3 by 7 and 5 by 2, and then adding the results.
$3(7)+5(2)=21+10=31$.