SOLUTION: Which number is not real? 1.) -8 2.) sqrt(-64) 3.) - sqrt(64) 4.) 3 times sqrt(-64) I already eliminated -8 and - sqrt(64) beacause I know they are real, I just don't unders

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: Which number is not real? 1.) -8 2.) sqrt(-64) 3.) - sqrt(64) 4.) 3 times sqrt(-64) I already eliminated -8 and - sqrt(64) beacause I know they are real, I just don't unders      Log On

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Question 414406: Which number is not real?
1.) -8
2.) sqrt(-64)
3.) - sqrt(64)
4.) 3 times sqrt(-64)
I already eliminated -8 and - sqrt(64) beacause I know they are real, I just don't understand the other two. Please help, Thank you!

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
2) and 4) are not real because they both
have sqrt%28-1%29 in the expressions
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2)
+sqrt%28-64%29+=+sqrt%2864%29%2Asqrt%28-1%29
sqrt%28-64%29+=+8i
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4)
3%2Asqrt%28-64%29+=+3%2A8%2Asqrt%28-1%29
3%2Asqrt%28-64%29+=+24i