Answers

2014-07-04T18:48:13+05:30
You can't substract the sqare root from a negative number. 
Always the result of a sqare root will be positive, cause will be in module |a|. And the result of the module is ALWAYS a positive number.

SO, the answer to you quesiton is "is's not possilbe" so substract the sqare root of -64.
You can substract the sqare root from 64 and the result is 8, cause 64=8x8, or 8^2.
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2014-07-04T18:49:38+05:30
Irs not possible bcoz it is acomplex no. and the topic complex no. is not in ur syallbus..
when u will come  in higher classes you will be learned about complex no..
so the ans. I NP...
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