7. (10 points) Calculate: $(100+15+17) \times(21+36+11)+(100-21-36-11) \times(15+17)=$
【Analysis】Find the common factor, then simplify the calculation continuously according to the distributive law of multiplication.
【Solution】Solution: $(100+15+17) \times(21+36+11)+(100-21-36-11) \times(15+17)$
$$
\begin{array}{l}
=100 \times(21+36+11)+(15+17) \times(21+36+11)+100 \times(15+17)-(21+36+11) \times(15+17) \\
=100 \times(21+36+11)+100 \times(15+17)+(15+17) \times(21+36+11)-(21+36+11) \times(15+17) \\
=100 \times(21+36+11)+100 \times(15+17) \\
=100 \times(21+36+11+15+17) \\
=100 \times 100 \\
=10000
\end{array}
$$

Therefore, the answer is: 10000.