Question

Answer 1

a: \(=\left(\sqrt{5}\right)^2-2^2=5-4=1\)

b: \(=3\left(\sqrt{7}+\sqrt{5}\right)\left(\sqrt{7}-\sqrt{5}\right)\)

=3(7-5)

=3*2=6

c: \(=\sqrt{5}\left(\sqrt{5}+\sqrt{3}\right)\left(\sqrt{5}-\sqrt{3}\right)\)

\(=\sqrt{5}\left(5-3\right)=2\sqrt{5}\)

d: \(=\left(4\sqrt{2}-5\sqrt{2}+3\sqrt{3}\right)\left(3\sqrt{3}+5\sqrt{2}-4\sqrt{2}\right)\)

\(=\left(3\sqrt{3}-\sqrt{2}\right)\left(3\sqrt{3}+\sqrt{2}\right)\)

=27-2=25