Question

How do you subtract `\sqrt { 40} - 3\sqrt { 90}`?

Answer 1

`- 7 sqrt 10`

Explanation:

`sqrt 4 sqrt 10 - 3 sqrt 9 sqrt 10 =`

`2 sqrt 10 - 3 * 3 sqrt 10 =`

`(2 - 9) sqrt 10 =`