\[Страница\ 74.\]
\[\boxed{\mathbf{11.}}\]
\[A \cup B = 1 + 5 + 3 = 9\ элементов.\]
\[Ответ:9\ элементов.\]
\[\boxed{\mathbf{12.}}\]
\[1\] | \[2\] | \[3\] | \[4\] |
---|---|---|---|
\[в\] | \[б\] | \[а\] | \[г\] |
\[\boxed{\mathbf{13.}}\]
\[67 \cdot 78 - 68 \cdot 67 =\]
\[= 67 \cdot (78 - 68) = 67 \cdot 10 =\]
\[= 670\]
\[45 \cdot 58 + 34 \cdot 45 + 8 \cdot 45 =\]
\[= 45 \cdot (58 + 34 + 8) =\]
\[= 45 \cdot 100 = 4500\]
\[134\ 000\ :670 = 13\ 400\ :67 =\]
\[= 200\]
\[4500 - 200 = 4300\]
\[\textbf{б)}\ \left( \left( 9^{3} - 7^{2} \right)\ :8 + 15 \right)^{2} = 10\ 000\]
\[9^{3} - 7^{2} = 729 - 49 = 680\]
\[680\ :8 = 85\]
\[85 + 15 = 100\]
\[100^{2} = 10\ 000\]