Question

Answer 1

\(A=\dfrac{\left(\sqrt{7}+\sqrt{3}\right)^2+\left(\sqrt{7}-\sqrt{3}\right)^2}{\left(\sqrt{7}-\sqrt{3}\right)\left(\sqrt{7}+\sqrt{3}\right)}\\ A=\dfrac{10+2\sqrt{21}+10-2\sqrt{21}}{4}=\dfrac{20}{4}=5\)

Lớp 12 à?

Answer 2

A=(√7+√3)2+(√7−√3)2(√7−√3)(√7+√3)A=10+2√21+10−2√214=204=5