Answer
$22-4\sqrt{30}$.
Work Step by Step
The given expression is
$=(2\sqrt{3}-\sqrt{10})^2$
Use the special formula $(A-B)^2=A^2-2AB+B^2$
We have $A=2\sqrt3$ and $B=\sqrt{10}$.
$=(2\sqrt3)^2-2(2\sqrt3)(\sqrt{10})+(\sqrt{10})^2$
Use product rule.
$=12-4\sqrt{30}+10$
Simplify.
$=22-4\sqrt{30}$.
