Question

Tìm x biết x= \(\sqrt{5+\sqrt{13+\sqrt{5+\sqrt{13}}}}\)

Answer 1

x= √5+√13+√5+√13=√5+√13+√5+√16=

 = √5+√13+√5+4=√5+√13+√9=√5+√13+3

Answer 2

x= \(\sqrt{5+\sqrt{13+\sqrt{5+\sqrt{13}}}}=\sqrt{5+\sqrt{13+\sqrt{5+\sqrt{16}}}}=\)

 = \(\sqrt{5+\sqrt{13+\sqrt{5+4}}}=\sqrt{5+\sqrt{13+\sqrt{9}}}=\)\(\sqrt{5+\sqrt{13+3}}\)

= \(\sqrt{5+\sqrt{16}}=\sqrt{5+4}=\sqrt{9}=3\)