How do you simplify #9sqrt 8 - sqrt72 + sqrt98#?

1 Answer
Sep 8, 2016

#19sqrt2#

Explanation:

Write the numbers under the roots as the product of their prime factors.

#9sqrt8 - sqrt72 + sqrt98#

=#9sqrt(2xx2xx2) - sqrt(2xx2xx2xx3xx3) + sqrt(7xx7xx2)#

Find the square roots where possible

=#9xx2sqrt2-2xx3sqrt2 +7sqrt2" "larr # there is a common factor

=#sqrt2(18-6+7)#

=#19sqrt2#