Решебник по математике 5 класс Бурмистрова рабочая тетрадь Часть 1, 2 Часть 1 | Страница 38

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\[\boxed{\mathbf{104.}}\]

\[\textbf{а)}\ (12 + 8) \cdot 31 =\]

\[= 12 \cdot 31 + 8 \cdot 31\]

\[\textbf{б)}\ (56 - 19) \cdot 42 =\]

\[= 56 \cdot 42 - 19 \cdot 42\]

\[\textbf{в)}\ (10 + 11) \cdot 99 =\]

\[= 10 \cdot 99 + 11 \cdot 99\]

\[\textbf{г)}\ (12 + 8) \cdot 4 = 12 \cdot 4 + 8 \cdot 4\]

\[\boxed{\mathbf{105.}}\]

\[\textbf{а)}\ 289 \cdot 109 + 311 \cdot 109 =\]

\[= (289 + 311) \cdot 109 =\]

\[= 600 \cdot 109 = 65\ 400\]

\[\textbf{б)}\ 5114 \cdot 587 + 2686 \cdot 587 - 800 \cdot 587 =\]

\[= (5114 + 2686 - 800) \cdot 587 =\]

\[= 7000 \cdot 587 = 4\ 109\ 000\]

\[\boxed{\mathbf{106.}}\]

\[\textbf{а)}\ 193 \cdot 9 = (200 - 7) \cdot 9 =\]

\[= 200 \cdot 9 - 7 \cdot 9 =\]

\[= 1800 - 63 = 1737\]

\[\textbf{б)}\ 92 \cdot 9 = (90 + 2) \cdot 9 =\]

\[= 90 \cdot 9 + 2 \cdot 9 =\]

\[= 810 + 18 = 828\]

\[\boxed{\mathbf{107.}}\]

\[\textbf{а)}\ \ 13 \cdot a + 7 \cdot a =\]

\[= (13 + 7) \cdot a = 20a\ \]

\[\textbf{б)}\ 77 \cdot b + 9 \cdot b =\]

\[= (77 + 9) \cdot b = 86b\]

\[\textbf{в)}\ 38 \cdot d - 8 \cdot d =\]

\[= (38 - 8) \cdot d = 30d\]

\[\textbf{г)}\ 107 \cdot c - 77 \cdot c =\]

\[= (107 - 77) \cdot c = 30c\]

\[\textbf{д)}\ 127 \cdot m + 8 \cdot m - 35 \cdot m =\]

\[= (127 + 8 - 35) \cdot m = 100m\]

\[\boxed{\mathbf{108.}}\]

\[\textbf{а)}\ 3 \cdot a + 7 \cdot a = 60\]

\[10 \cdot a = 60\]

\[a = 60\ :10\]

\[a = 6.\]

\[\textbf{б)}\ 77 \cdot b - 12 \cdot b = 650\]

\[65 \cdot b = 650\]

\[b = 650\ :65\]

\[b = 10.\]

\[\textbf{в)}\ 38 \cdot d + 6 \cdot d - 4 \cdot d = 240\]

\[40 \cdot d = 240\]

\[d = 240\ :40\]

\[d = 6.\]