Question 136727
(√{6}+2√{2})(4√{6}-3√{2})
Use FOIL:
F: =4*6 = 24
O: =-3sqrt12 = -6sqrt(3)
I: = 4sqrt(12) = 8sqrt(3)
L: = -6*2 = -12
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Combine to get: 12 + 2sqrt(3)
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The other one that seems a little easier that I can not figure is 
√{81}{x12y8z10}
 = 9x^12y^8z^10
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Cheers,
Stan H.