Решебник по математике 5 класс Мерзляк ФГОС Задание 545

 

\[\boxed{\mathbf{545\ (545)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]

\(1)\ 14a \cdot 6b = 84ab\)

\[при\ a = 2;\ \ b = 3:\]

\[84 \cdot 2 \cdot 3 = 84 \cdot 6 = 504.\]

\(2)\ 25m \cdot 3n = 75mn\)

\[при\ m = 8;\ \ n = 1:\]

\[75 \cdot 8 \cdot 1 = 600.\]

\[3)\ 5x + 8x - 3x = 5x + 5x =\]

\[= 10x\]

\[при\ x = 17:\]

\[10x = 10 \cdot 17 = 170.\]

\[4)\ 16y - y + 5y = 15y + 5y =\]

\[= 20y\]

\[при\ y = 23:\]

\[20y = 20 \cdot 23 = 460.\]

\[\boxed{\ \mathbf{545\ (490)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]

\[1)\ 8 \cdot (x - 14) = 56\]

\[x - 14 = 56\ :8\]

\[x - 14 = 7\]

\[x = 7 + 14\]

\[x = 21\]

\[Ответ:21.\]

\[2)\ (46 - x) \cdot 19 = 418\]

\[46 - x = 418\ :19\]

\[46 - x = 22\]

\[x = 46 - 22\]

\[x = 24\]

\[Ответ:24.\]

\[3)\ 9 \cdot (143 - 13x) = 234\]

\[143 - 13x = 234\ :9\]

\[143 - 13x = 26\]

\[13x = 143 - 26\]

\[13x = 117\]

\[x = 117\ :13\]

\[x = 9\]

\[Ответ:9.\]

\[4)\ 17 \cdot (5x - 16) = 238\]

\[5x - 16 = 238\ :17\]

\[5x - 16 = 14\]

\[5x = 14 + 16\]

\[5x = 30\]

\[x = 30\ :5\]

\[x = 6\]

\[Ответ:6.\]