Question #6901d

1 Answer
Feb 23, 2018

#4isqrt(7)#

Explanation:

To simplify the expression #2sqrt(-28)#, you have to use the term #i#.

#i= sqrt(-1)# which is the imaginary unit.

You can rearrange the equation into:

#2sqrt(-1*28)#
#2sqrt(-1)sqrt(28)#
#2isqrt(28)#

Now to simplify inside the radical, you need to factor out a perfect square from 28. The only one that comes to mind is four. Make 28 into #4*7#.

#2isqrt(4*7)#
#2isqrt(4)sqrt(7)#

The square root of 4 becomes 2. Hence:

#2i *2sqrt(7)#

#4isqrt7#