Question

Simplify (√7+√5)(√7-√5)

Answer 1

Root7 sq - root5sq
Which is equal to 2

Answer 2

Answer:

$( \sqrt{7 } + \sqrt{5} )( \sqrt{7 - \sqrt{5} } )$

=

$(a + b)(a - b) = a {}^{2} - \: b {}^{2}$

=

$7 - 5 = 2$