Question

3√5а - √20а + 4√45а = ?​

Answer 1

3√5а - √20а + 4√45а = 3$\sqrt{5}$a - $\sqrt{4*5}$a + 4$\sqrt{9*5}$a =  3$\sqrt{5}$a -2 $\sqrt5}$a + 12$\sqrt{5}$a = 13$\sqrt{5}$a