# How do you simplify # (4) / ( sqrt(5)+sqrt(5) )#?

##### 1 Answer

Oct 16, 2015

#### Explanation:

Your starting expression is

#4/(sqrt(5) + sqrt(5))#

Notice that you can combine the two radical terms in the denominator to get

#sqrt(5) + sqrt(5) = sqrt(5) * (1 + 1) = 2sqrt(5)#

The expression becomes

#4/(2sqrt(5)) = 2/sqrt(5)#

Next, *rationalize the denominator* by multiplyg the fraction by

#2/sqrt(5) * sqrt(5)/sqrt(5) = (2sqrt(5))/(sqrt(5) * sqrt(5)) = color(green)((2sqrt(5))/5)#