Chapter 10 - Radical Expressions and Equations - 10-3 Operations With Radical Expressions - Practice and Problem-Solving Exercises - Page 629: 29

The answer is $62-20\sqrt6$.

We can simplify the expression as follows: $=(5\sqrt2-2\sqrt3)^{2}$ $=(5\sqrt2)^{2}+(2\sqrt3)^{2}-2*5\sqrt2*2\sqrt3$ (since $(a-b)^{2}=a^{2}+b^{2}-2ab)$ $=(25*2)+(4*3)-20\sqrt6$ $=50+12-20\sqrt6$ $=62-20\sqrt6$.