7.2. Find the minimum value of the expression $\frac{5 x^{2}-8 x y+5 y^{2}-10 x+14 y+55}{\left(9-25 x^{2}+10 x y-y^{2}\right)^{5 / 2}}$. Round the answer to the nearest hundredths if necessary.
Answer: 0.19 (exact value: $\frac{5}{27}$ ).