How do you simplify $(6 + \sqrt{7}) (6 - \sqrt{7})$ $(6+sqrt 7)(6-sqrt 7)$ ?

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Answer 1 · 2016-02-13T17:58:54

$= 29$ $=color(blue)(29$

$(6 + \sqrt{7}) (6 - \sqrt{7})$ $(6+sqrt7)(6-sqrt7)$

The above expression is of the form
$(a + b) (a - b) = a^{2} - b^{2}$ $color(blue)((a+b)(a-b) = a^2 - b^2$

$a = 6, b = \sqrt{7}$ $color(blue)(a=6, b=sqrt7$

So,
$(6 + \sqrt{7}) (6 - \sqrt{7}) = 6^{2} - {(\sqrt{7})}^{2}$ $(6+sqrt7)(6-sqrt7) = color(blue)(6^2 - (sqrt7)^2$

$= 36 - 7$ $=36-7$

$= 29$ $=29$

How do you simplify (6+√7)(6−√7)(6+sqrt 7)(6-sqrt 7)?