How do you simplify #-2sqrt20+2sqrt18-2sqrt5#?

1 Answer
Feb 21, 2017

#= 6( sqrt 2 -sqrt 5) #

Explanation:

#-2 sqrt 20 + 2 sqrt 18 -2 sqrt 5#

#= -2 sqrt (4 * 5) + 2 sqrt (9 * 2) -2 sqrt 5#

#= -2 sqrt 4 * sqrt 5 + 2 sqrt 9 * sqrt 2 -2 sqrt 5#

#= -2 * 2 * sqrt 5 + 2 * 3 * sqrt 2 -2 sqrt 5#

#= -4 sqrt 5 + 6 sqrt 2 -2 sqrt 5#

#= -6 sqrt 5 + 6 sqrt 2 = 6 sqrt 2 - 6 sqrt 5#

#= 6( sqrt 2 -sqrt 5) #