How do you simplify $(3+sqrt 5)(3-sqrt 5)$ ?

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Answer 1 · 2015-10-16T02:05:35

$(3+sqrt 5)(3-sqrt 5)=4$

$(3+sqrt 5)(3-sqrt 5)$

This is an example of the difference of squares, $(a^2-b^2)=(a+b)(a-b)$ , where $a=3 and b=sqrt5$ .

$(3^2-sqrt(5^2))=$

$9-sqrt(5^2)$

Apply the square root rule $sqrt(x^2)=x$ .

$9-5=4$

How do you simplify (3+sqrt 5)(3-sqrt 5) (3+sqrt 5)(3-sqrt 5) ?