30.設\(a^{1/2} - a^{-1/2} = 3\) ,求\( \frac{a^2 + a^{-2} - 1}{a^{3/2} - a^{-3/2} + 4} \)的值為何?(A) 59/40(B) 59/20(C) 59/10(D) 20/59