Question 85292
(sq.root of 3 + sq.root of 5)(sq.root of 3 + sq.root of 5)
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(sqrt3 + sqrt5)(sqrt3 + sqrt5)

Use FOIL:
F: sqrt3*sqrt3 = 3
O: sqrt3*sqrt5 = sqrt15
I: sqrt5*sqrt3 = sqrt15
L; sqrt5*sqrt5 = 5
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Combine like terms to get:
8 + 2sqrt15
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Cheers,
Stan H.