ГДЗ по математике 5 класс Ткачева рабочая тетрадь | Страница 30

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

\[1)\ 32 \cdot 9 + 68 \cdot 9 =\]

\[= (32 + 68) \cdot 9 =\]

\[= 100 \cdot 9 = 900\]

\[2)\ 167 \cdot 8 + 33 \cdot 8 =\]

\[= (167 + 33) \cdot 8 =\]

\[= 200 \cdot 8 = 1600\]

\[3)\ 254 \cdot 12 - 12 \cdot 54 =\]

\[= 12 \cdot (254 - 54) =\]

\[= 12 \cdot 200 = 2400\]

\[4)\ 32 \cdot 146 - 46 \cdot 32 =\]

\[= 32 \cdot (146 - 46) =\]

\[= 32 \cdot 100 = 3200\]

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

\[1)\ (13 + a) \cdot 6 = 13 \cdot 6 + a \cdot 6 =\]

\[= 78 + a \cdot 6\]

\[2)\ (b + 24) \cdot 3 = b \cdot 3 + 24 \cdot 3 =\]

\[= b \cdot 3 + 72\]

\[3)\ 5 \cdot (x - 15) = 5 \cdot x - 5 \cdot 15 =\]

\[= 5x - 75\]

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

\[1)\ 63 \cdot a + 37 \cdot a =\]

\[= a \cdot (63 + 37) = a \cdot 100\]

\[a = 49:\]

\[a \cdot 100 = 49 \cdot 100 = 4900.\]

\[2)\ 281 \cdot a - 81 \cdot a =\]

\[= a \cdot (281 - 81) = a \cdot 200\]

\[a = 49:\]

\[a \cdot 200 = 49 \cdot 200 = 9400.\]

\[\boxed{\mathbf{4.}}\]

\[1)\ 99 \cdot 56 = (100 - 1) \cdot 56 =\]

\[= 100 \cdot 56 - 1 \cdot 56 =\]

\[= 5600 - 56 = 5544\]

\[2)\ 102 \cdot 27 = (100 + 2) \cdot 27 =\]

\[= 100 \cdot 27 + 2 \cdot 27 =\]

\[= 2700 + 54 = 2754\]

\[\mathbf{14.1.\ Действие\ деления}\]