Школьник
Студент
Учитель
Личный кабинет
Назад
Вычисления
Банк ОГЭ
Скопировать ссылку
9e35570c
Найдите значение выражения
3
⋅
21
⋅
28
\sqrt{3}\cdot \sqrt{21}\cdot \sqrt{28}
3
⋅
21
⋅
28
Ответ:
Ответить
Показать ответ
Ответ
Скрыть решение
Решение
Сообщить об ошибке
Решение
3
⋅
21
⋅
28
=
3
⋅
3
⋅
7
⋅
4
⋅
7
=
3
⋅
3
⋅
7
⋅
2
⋅
7
=
2
⋅
(
3
⋅
3
)
⋅
(
7
⋅
7
)
=
2
⋅
3
⋅
7
=
42
\begin{aligned}
{}& \sqrt{3}\cdot \sqrt{21}\cdot \sqrt{28} = \sqrt{3}\cdot \sqrt{3\cdot 7}\cdot \sqrt{4\cdot 7} = \\
& \sqrt{3}\cdot \sqrt{3}\cdot \sqrt{7}\cdot 2\cdot \sqrt{7} = \\
& 2\cdot (\sqrt{3}\cdot\sqrt{3})\cdot (\sqrt{7}\cdot\sqrt{7}) = \\
& 2\cdot 3\cdot 7 = 42
\end{aligned}
3
⋅
21
⋅
28
=
3
⋅
3
⋅
7
⋅
4
⋅
7
=
3
⋅
3
⋅
7
⋅
2
⋅
7
=
2
⋅
(
3
⋅
3
)
⋅
(
7
⋅
7
)
=
2
⋅
3
⋅
7
=
42
Ответ:
42
42
42
.
