Школьник
Студент
Учитель
Личный кабинет
Назад
Вычисления
Банк ОГЭ
Скопировать ссылку
b327e7e6
Найдите значение выражения
5
3
⋅
4
7
⋅
21
5\sqrt{3}\cdot 4\sqrt{7}\cdot \sqrt{21}
5
3
⋅
4
7
⋅
21
Ответ:
Ответить
Показать ответ
Ответ
Показать решение
Решение
Сообщить об ошибке
Решение
5
3
⋅
4
7
⋅
21
=
5
⋅
3
⋅
4
⋅
7
⋅
3
⋅
7
=
5
⋅
4
⋅
3
⋅
7
⋅
3
⋅
7
=
20
⋅
(
3
⋅
3
)
⋅
(
7
⋅
7
)
=
20
⋅
3
⋅
7
=
420
\begin{aligned}
{}& 5\sqrt{3}\cdot 4\sqrt{7}\cdot \sqrt{21} = 5\cdot \sqrt{3}\cdot 4\cdot \sqrt{7}\cdot \sqrt{3\cdot 7} = \\
& 5\cdot 4\cdot \sqrt{3}\cdot \sqrt{7}\cdot \sqrt{3}\cdot \sqrt{7} = \\
& 20\cdot (\sqrt{3}\cdot\sqrt{3})\cdot (\sqrt{7}\cdot\sqrt{7}) = \\
& 20\cdot 3\cdot 7 = 420
\end{aligned}
5
3
⋅
4
7
⋅
21
=
5
⋅
3
⋅
4
⋅
7
⋅
3
⋅
7
=
5
⋅
4
⋅
3
⋅
7
⋅
3
⋅
7
=
20
⋅
(
3
⋅
3
)
⋅
(
7
⋅
7
)
=
20
⋅
3
⋅
7
=
420
Ответ:
420
420
420
.
