\[\mathbf{Страница\ 46.}\]
\[\boxed{\mathbf{13.}}\]
\[\textbf{а)} - 18 + ( - 45) = - 63\]
\[- 16 + 9 = - 7\]
\[17 + ( - 5) = 12\]
\[\textbf{б)}\ 90 + ( - 130) = - 40\]
\[1 + ( - 7) = - 6\]
\[5 + ( - 10) = - 5\]
\[\textbf{в)}\ 13 + ( - 7) = 6\]
\[- 40 + 30 = - 10\]
\[- 15 + 20 = 5\]
\[\textbf{г)}\ 60 + ( - 37) = 23\]
\[14 + ( - 18) = - 4\]
\[- 28 + 15 = - 13\]
\[\boxed{\mathbf{14.}}\]
\[\textbf{а)}\ Сумма\ чисел\ увеличится\ на:\]
\[5 + ( - 3) = 2.\]
\[Ответ:увеличится\ на\ 2.\]
\[\textbf{б)}\ Сумма\ чисел\ уменьшится\ на:\]
\[( - 11) + ( - 7) = - 18.\]
\[Ответ:уменьшится\ на\ 18.\]
\[\boxed{\mathbf{15.}}\]
\[x + 8 < 0\]
\[x < - 8\]
\[x = - 9;\ - 10;\ - 11;\ldots\]
\[Ответ:при\ x = - 9; - 10; - 11;\ldots\]
\[\boxed{\mathbf{16.}}\]
\[y + 1 > 0\]
\[y > - 1\]
\[y = 0;1;2;3;\ldots\]
\[Ответ:при\ y = 0;1;2;3;\ldots\]
\[\boxed{\mathbf{17.}}\]
\[\textbf{а)}\ x - 10 = - 2\]
\[x = - 2 + 10\]
\[x = 8.\]
\[Ответ:8.\]
\[\textbf{б)}\ y - 13 = - 37\]
\[y = - 37 + 13\]
\[y = - 24.\]
\[Ответ:\ - 24.\]
\[\textbf{в)}\ y - 48 = - 11\]
\[y = - 11 + 48\]
\[y = 37.\]
\[Ответ:\ 37.\]