Question

\(\sqrt{9a}\)\(\left(5-3\sqrt{a}\right)-5\left(3\sqrt{a}-5\right)\)

Answer 1

\(\sqrt{9a}\left(5-3\sqrt{a}\right)-5\left(3\sqrt{a}-5\right)\\ =\sqrt{9a}\left(5-3\sqrt{a}\right)+5\left(5-3\sqrt{a}\right)\\ =\left(5-3\sqrt{a}\right)\left(\sqrt{9a}+5\right)\)

Answer 2

\(\sqrt{9a}\left(5-3\sqrt{a}\right)-5\left(3\sqrt{a}-5\right)\\ =3\sqrt{a}\left(5-3\sqrt{a}\right)+5\left(5-3\sqrt{a}\right)\\ =\left(5-3\sqrt{a}\right)\left(5+3\sqrt{a}\right)\\ =5^2-\left(3\sqrt{a}\right)^2\\ =25-9a\)