Решебник по математике 6 класс Ерина Никольский рабочая тетрадь Часть 1, 2 Часть 1 | Страница 54

\[\mathbf{Страница\ 54.}\]

\[\boxed{\mathbf{6.}}\]

\[a \cdot b\]

\[6;\ - 28;\ - 40;\ - 80;\]

\[14;\ \frac{2}{5};\ \frac{7}{100};\ \frac{3}{5};\ \ \]

\[1;\ \ 128;\ - 132;120.\]

\[\boxed{\mathbf{7.}}\]

\[\textbf{а)} - 6 \cdot 2 = - 12\]

\[- 4 \cdot ( - 5) = 20\]

\[7 \cdot ( - 3) = - 21\]

\[\textbf{б)} - 7 \cdot 1 = - 7\]

\[- 5 \cdot ( - 1) = 5\]

\[6 \cdot ( - 1) = - 6\]

\[\textbf{в)} - 5 \cdot 4 = - 20\]

\[0 \cdot ( - 10) = 0\]

\[- 9 \cdot ( - 3) = 27\]

\[\boxed{\mathbf{8.}}\]

\[\textbf{а)}\ ( - 2)^{3} = - 8\]

\[( - 5)^{2} = 25\]

\[( - 1)^{2} = 1\]

\[\left( 2\frac{3}{4} \right)^{2} = \frac{11}{4} \cdot \frac{11}{4} = \frac{121}{16} = 7\frac{9}{16}\]

\[\left( \frac{5}{7} \right)^{2} = \frac{25}{49}\]

\[\textbf{б)}\ \left( \frac{3}{10} \right)^{3} = \frac{27}{1000}\]

\[( - 9)^{2} = 81\]

\[( - 7)^{3} = - 343\]

\[\left( 4\frac{2}{3} \right)^{2} = \frac{14}{3} \cdot \frac{14}{3} = \frac{196}{9} = 21\frac{7}{9}\]

\[\left( \frac{11}{12} \right)^{2} = \frac{121}{144}\]

\[\boxed{\mathbf{9.}}\]

\[\textbf{а)}\ ( - 7) \cdot ( - 2) > 0\]

\[- 9 \cdot 5 < 0\]

\[- 6 \cdot ( - 8) > 0\]

\[- 20 \cdot ( - 20) > 0\]

\[\textbf{б)}\ 7 \cdot ( - 2) < 0\]

\[8 \cdot ( - 9) < 0\]

\[- 1 \cdot ( - 11) > 0\]

\[- 2 \cdot 3 < 0\]

\[\textbf{в)} - 13 \cdot 0 = 0\]

\[- 16 \cdot 1 < 0\]

\[0 \cdot ( - 5) = 0\]

\[- 7 \cdot ( - 6) > 0\]

\[\boxed{\mathbf{10.}}\]

\[y = x^{2} - 2x - 3\]

\[y = ( - 2)^{2} - 2 \cdot ( - 2) - 3 =\]

\[= 4 + 4 - 3 = 5\]

\[y = ( - 1)^{2} - 2 \cdot ( - 1) - 3 =\]

\[= 1 + 2 - 3 = 0\]

\[y = 0 - 2 \cdot 0 - 3 = - 3\]

\[y = 1^{2} - 2 \cdot 1 - 3 =\]

\[= 1 - 2 - 3 = - 4\]

\[y = 2^{2} - 2 \cdot 2 - 3 =\]

\[= 4 - 4 - 3 = - 3\]

\[y = \left( \frac{1}{2} \right)^{2} - 2 \cdot \frac{1}{2} - 3 =\]

\[= \frac{1}{4} - 1 - 3 =\]

\[= - 4 + \frac{1}{4} = - 3\frac{3}{4}\]

\[y = \left( \frac{1}{3} \right)^{2} - 2 \cdot \frac{1}{3} - 3 =\]

\[= \frac{1}{9} - \frac{2}{3} - 3 =\]

\[= - 3\frac{6}{9} + \frac{1}{9} = - 3\frac{5}{9}\]

\[y = \left( \frac{1}{4} \right)^{2} - 2 \cdot \frac{1}{4} - 3 =\]

\[= \frac{1}{16} - \frac{1}{2} - 3 =\]

\[= - 3\frac{8}{16} + \frac{1}{16} = - 3\frac{7}{16}\]

\[y = \left( \frac{1}{5} \right)^{2} - 2 \cdot \frac{1}{5} - 3 =\]

\[= \frac{1}{25} - \frac{2}{5} - 3 =\]

\[= - 3\frac{10}{25} + \frac{1}{25} = - 3\frac{9}{25}\]