How do you divide #sqrt7/(sqrt34+5)#?

1 Answer
Mar 24, 2015

This can be simplified a bit by removing the radical from the denominator.
To do this recall that
#(a + b) * (a - b) = (a^2 - b^2)#
or, for our particular case
#(sqrt(34) + 5) * (sqrt(34) - 5) = 34 -25 = 9#

Applying this to the original problem:
#sqrt(7)/(sqrt(34)+5)#

#= sqrt(7)/(sqrt(34)+5) * (sqrt(34)-5)/(sqrt(34)-5)#

#= ((sqrt(7)) (sqrt(34) - 5))/9#

(The numerator could be multiplied but doing so provides not obvious simplification.)