Решебник по математике 5 класс Ерина. Никольский рабочая тетрадь Часть 1, 2 Часть 1 | Страница 17

\[\mathbf{Страница\ 17.}\]

\[\boxed{\mathbf{12.}}\]

\[100 - 68 = 32\]

\[302 - 80 = 222\]

\[103 + 44 = 147\]

\[12 + 888 = 900\]

\[850 - 805 = 45\]

\[1035 + 3054 = 4089\]

\[\boxed{\mathbf{13.}}\]

\[\textbf{а)}\ (66 + 48) - 36 =\]

\[= (66 - 36) + 48 =\]

\[= 30 + 48 = 78\]

\[\textbf{б)}\ (238 + 49) - 29 =\]

\[= 238 + (49 - 29) =\]

\[= 238 + 20 = 258\]

\[\textbf{в)}\ 182 - (52 + 46) =\]

\[= (182 - 52) - 46 =\]

\[= 130 - 46 = 84\]

\[\textbf{г)}\ 328 - (77 + 88) =\]

\[= (328 - 88) - 77 =\]

\[= 240 - 77 = 240 - 40 - 37 =\]

\[= 163\]

\[\boxed{\mathbf{14.}}\]

\[Выучите\ правило.\]

\[\boxed{\mathbf{15.}}\]

\[\textbf{а)}\ 68 - 19 =\]

\[= (68 + 1) - (19 + 1) =\]

\[= 69 - 20 = 49\]

\[\textbf{б)}\ 300 - 96 =\]

\[= (300 + 4) - (96 + 4) =\]

\[= 304 - 100 = 204\]

\[\textbf{в)}\ 708 - 499 =\]

\[= (708 + 1) - (499 + 1) =\]

\[= 709 - 500 = 209\]

\[\textbf{г)}\ 504 - 99 =\]

\[= (504 + 1) - (99 + 1) =\]

\[= 505 - 100 = 405\]

\[\textbf{д)}\ 225 - 98 =\]

\[= (225 + 2) - (98 + 2) =\]

\[= 227 - 100 = 127\]

\[\boxed{\mathbf{16.}}\]

\[\textbf{а)}\ x - 4041 = 2368\]

\[x = 2368 + 4041\]

\[x = 6409.\]

\[Ответ:6409.\]

\[\textbf{б)}\ 10\ 801 - x = 3807\]

\[x = 10\ 801 - 3807\]

\[x = 6994.\]

\[Ответ:\ 6994.\]