\(\boxed{\text{Вопрос}\text{\ }\text{на}\text{\ }\text{стр}\text{.\ 12}}\)
\[9 \cdot (4 \cdot 25) = 9 \cdot 100 = 900\]
\[15 \cdot (4 \cdot 9) = (15 \cdot 4) \cdot 9 =\]
\[= 60 \cdot 9 = 540\]
\[11 \cdot 10 \cdot 3 = (11 \cdot 3) \cdot 10 =\]
\[= 33 \cdot 10 = 330\]
\[10 \cdot (29 \cdot 2) = 10 \cdot 58 = 580\]