Question

\(\sqrt{9a}+\sqrt{81a}+3\sqrt{25a}-16\sqrt{49a}\) (với a≥0)

Answer 1

\(\sqrt{9a}+\sqrt{81a}+3\sqrt{25a}-16\sqrt{49a}\)

\(=3\sqrt{a}+9\sqrt{a}+15\sqrt{a}+112\sqrt{a}\)

\(=139\sqrt{a}\)