How do you simplify #sqrt 7 - 2sqrt63#?

1 Answer
Apr 11, 2016

Answer:

#-5sqrt7#

Explanation:

Recall that: #sqrt(mn)=sqrtm*sqrtn#

Using this rule, we can rewrite your problem as:

#sqrt7-2*sqrt(9*7)#

Simplifying this further by taking the #sqrt9# outside, we get:

#sqrt7-2*3sqrt(7)#
#=sqrt7-6*sqrt(7)#

If we consider #sqrtn# to equal #1*sqrtn# we can further simplify the equation:

#sqrt7-6sqrt(7)#
#=1*sqrt7-6*sqrt(7)#

Therefore:

#(1-6)*sqrt7#

Completely simplified:

#=-5sqrt7#