Question #6901d

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Answer 1 · 2018-02-23T02:16:09

#4isqrt(7)#

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#