Question #15e2b

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Answer 1 · 2017-10-21T00:47:51

#9^3sqrt(5)-6^3sqrt(5)=513sqrt(5)#

First of all, let's review what we know about subtracting square root expressions with the same radicand:

#asqrt(b)-csqrt(b)=(a-c)sqrt(b)#

With this in mind,

#9^3sqrt(5)-6^3sqrt(5)=(9^3-6^3)sqrt(5)#

Aha! Now, by doing some computation, we can figure out that

#9^3-6^3=513#

And so our answer is:

#513sqrt(5)#