How do you simplify #4sqrt5-2sqrt5#?

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Answer 1 · 2016-12-24T13:59:35

#2sqrt(5)#

#4sqrt(5)-2sqrt(5)#

these are like terms- they are both multiples of the radical #sqrt(5)#.

collecting like terms gives you #(4-2) * sqrt(5)#

#= 2 * sqrt(5)#

#=2sqrt(5)#

Answer 2 · 2016-12-24T13:59:43

#4 sqrt5 - 2 sqrt5 = 2 sqrt5#

The question is much easier than it looks at first glance.

Compare this with a question like:
4 bags - 2 bags = 2 bags

In algebra we can work with like terms:

#4x - 2x= 2x#

#4 square - 2 square = 2 square#

In this case you can consider #sqrt5# in each term as being like terms.

#4 sqrt5 - 2 sqrt5 = 2 sqrt5#

#sqrt5# is an irrational number and cannot be written exactly, so it is better to use it like this.