## Elementary Algebra

We use the rule $(a+b)(a-b)=a^{2}-b^{2}$ to multiply the two terms: $(2\sqrt 3+\sqrt 5)(2\sqrt 3-\sqrt 5)$ =$(2\sqrt 3)^{2}-(\sqrt 5)^{2}$ =$[2^{2}\times (\sqrt 3)^{2}]-(\sqrt 5)^{2}$ =$[4\times 3]-(5)$ =$[12]-(5)$ =$7$ Therefore, the question statement is true.