1. (3 points) $20092009 \times 2010-20102010 \times 2009$;
$$
\begin{array}{l}
\text { 1. (3 points) } 20092009 \times 2010-20102010 \times 2009 \text {; } \\
=2009 \times 10001 \times 2010-2010 \times 10001 \times 2009 \text {, } \\
=0 \text {. } \\
\end{array}
$$
.

【Answer】Solution: $20092009 \times 2010-20102010 \times 2009$,
