Please help....?

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2 Answers
Apr 9, 2018

#+-5i#

Explanation:

Remember: #sqrt-1=i# and #sqrt(ab)=sqrt(a*b)#

25 is a perfect square (#5^2=25#, #(-5)^2=25#), separate that from -1

#+-sqrt(25*-1) rarr sqrt-1# is #i#

#+- 5i rarr# The #+-# symbol shows that the answer can be negative or positive

Apr 9, 2018

#+-5i#

Explanation:

Remember #i=sqrt(-1#

So:
#+-sqrt(-25)=#

#+-sqrt(-1*25)=#

#+-isqrt(25)=#

#+-5i#