#### Answer

7

#### Work Step by Step

$(2\sqrt{3}+\sqrt5)(2\sqrt{3}-\sqrt5)$
Use the FOIL method to multiply the binomial.
Multiply the First terms, the Outside terms, the Inside terms, and the Last terms.
$(2\sqrt{3}\times2\sqrt{3})+(2\sqrt3\times(-\sqrt5))+(2\sqrt3\times\sqrt5)+(\sqrt5\times(-\sqrt5))$
Simplify.
$12-2\sqrt{15}+2\sqrt{15}-5$
Combine like terms/like radicals.
$7$