Решебник по математике 5 класс Ткачева ФГОС рабочая тетрадь Часть 1, 2 Часть 1 | Страница 25

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\[\boxed{\mathbf{5}.}\]

\[\textbf{а)}\ 364 + a + 136 = a +\]

\[+ (364 + 136) = a + 500\]

\[\textbf{б)}\ 67 - (47 + b) =\]

\[= (67 - 47) - b = 20 - b\]

\[\textbf{в)}\ c - 149 - 251 = c -\]

\[- (149 + 251) = c - 400\]

\[\textbf{г)}\ (n + 251) - 30 = n +\]

\[+ (251 - 30) = n + 221\]

\[\textbf{д)}\ 98 + (m - 38) = (98 - 38) +\]

\[+ m = 60 + m\ \]

\[11.\ Уравнение\]

\[\boxed{\mathbf{1}.}\]

\[Подчеркните:\]

\[58 + 54 = 112\]

\[94 - 27 = 67\]

\[\boxed{\mathbf{2}.}\]

\[3 \cdot x - 12 = 30\]

\[x = 10:\]

\[3 \cdot 10 - 12 = 30\]

\[18 \neq 30.\]

\[x = 12:\]

\[3 \cdot 12 - 12 = 30\]

\[24 \neq 30.\]

\[x = 13:\]

\[3 \cdot 13 - 12 = 30\]

\[27 \neq 30.\]

\[x = 14:\]

\[3 \cdot 14 - 12 = 30\]

\[30 = 30.\]

\[Ответ:14 - корень\ уравнения.\]

\[\boxed{\mathbf{3}.}\]

\[\textbf{а)}\ x + 48 = 76\]

\[x = 76 - 48\]

\[x = 28.\]

\[\textbf{б)}\ 29 + x = 61\]

\[x = 61 - 29\]

\[x = 32.\]

\[\textbf{в)}\ 121 - x = 22\]

\[x = 121 - 22\]

\[x = 99.\]

\[\textbf{г)}\ x - 34 = 68\]

\[x = 68 + 34\]

\[x = 102.\]