If \( \displaystyle \lim_{x \to 1} \frac{(5x+1)^{1/3} - (x+5)^{1/3}}{(2x+3)^{1/2} - (x+4)^{1/2}} = \frac{m\sqrt{5}}{n(2n)^{2/3}} \), where \( \gcd(m,n) = 1 \), then \( 8m + 12n \) is equal to ________.