e.) (2+sqrt (7))/(2a+sqrt (7a^2)) where a is a positive integer

Given a > 0, $\sqrt{a^2} = a$, so:<br /><br />$\frac{2+\sqrt{7}}{2a+a\sqrt{7}} = \frac{2+\sqrt{7}}{a(2+\sqrt{7})} = \frac{1}{a}$<br />