Question

\(\left(3\sqrt{20}-\sqrt{125}-15\sqrt{\dfrac{1}{5}}\right)\) . \(\sqrt{5}\)

Answer 1

`(3sqrt{20} - sqrt{125} - 15 sqrt{1/5}) . sqrt{5}`

`=(6sqrt{5} - 5sqrt{5} - 3sqrt{5}) . sqrt{5}`

`=(6- 5 - 3)sqrt{5} . sqrt{5}`

`=(-2)sqrt{5} . sqrt{5}`

`= -2 . 5`

`= -10`

Answer 2

\(\left(3\sqrt{20}-\sqrt{125}-15\sqrt{\dfrac{1}{5}}\right)\cdot\sqrt{5}\)

\(=3\sqrt{100}-\sqrt{625}-15\)

\(=3\cdot10-25-15\)

\(=30-25-15\)

\(=-10\)