human
Prove statements involving odd and even numbers Which of these shows part of the proof that the sum of two odd numbers is even? \( \begin{array}{l}(2 n-1)(2 m+1) \\ =4 m n+2 n-2 m-1 \\ =2(2 m n-n-m)+1\end{array} \)
gpt
Does not know the meaning of the word "sum"