How do you simplify $4 /(sqrt7 + sqrt 3)$ ?

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Answer 1 · 2017-04-03T12:23:16

You multiply the both halves by $sqrt7-sqrt3$ and use the special product $(A+B)(A-B)=A^2-B^2$

$=4/(sqrt7-sqrt3)xx(sqrt7-sqrt3)/(sqrt7-sqrt3)$

$=(4(sqrt7-sqrt3))/((sqrt7+sqrt3)(sqrt7-sqrt3))$

$=(4(sqrt7-sqrt3))/(sqrt7^2-sqrt3^2)=(4(sqrt7-sqrt3))/(7-3)=$

$=(cancel4(sqrt7-sqrt3))/cancel4=sqrt7-sqrt3$

How do you simplify 4 /(sqrt7 + sqrt 3)4 /(sqrt7 + sqrt 3)?