Question

How do you simplify `sqrt7 - sqrt63`?

Answer 1

`=-2sqrt7`

Explanation:

`sqrt7 - sqrt63" "larr` write 63 as the product of factors

`=sqrt7- sqrt(3xx3xx7)" "larr sqrt (3^2) = 3`

`= sqrt7 - 3sqrt7" "larr 1-3 = -2`

`=-2sqrt7`