How do you simplify $(sqrt 5 + 9 sqrt2)(4 sqrt5 - sqrt 2)$ ?

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Answer 1 · 2016-05-29T16:29:12

$(sqrt5+9sqrt2)(4sqrt5-sqrt2)=2+35sqrt10$

$(sqrt5+9sqrt2)(4sqrt5-sqrt2)$

$=4sqrt5*sqrt5-sqrt5*sqrt2+9sqrt2*4sqrt5-9sqrt2*sqrt2$

$=4(sqrt5)^2-sqrt10+36sqrt10-9(sqrt2)^2$

$=4*5+35sqrt10-9*2$

$=20+35sqrt10-18$

$=2+35sqrt10$

How do you simplify (sqrt 5 + 9 sqrt2)(4 sqrt5 - sqrt 2)(sqrt 5 + 9 sqrt2)(4 sqrt5 - sqrt 2)?