Question

Thực hiện phép tính:

\(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)

Answer 1

\(A=\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)

\(A^2=8+2\sqrt{16-10-2\sqrt{5}}=8+2\sqrt{6-2\sqrt{5}}=8+2\sqrt{\left(\sqrt{5}-1\right)^2}\)

\(A^2=8+2\sqrt{5}-2=6+2\sqrt{5}=\sqrt{5}+1\)

\(\Rightarrow A=1+\sqrt{5}\)

Answer 2

Đặt BT đầu=a,BT sau bằng b,tổng bằng x,ta có:x=a+b

a^2+b^2=8 ;ab=căn 5-1

suy ra (a+b)^2-2ab=8>>>x^2-2 căn 5+2=8>>>x^2=6+2 căn 5 >>>x=căn 5+1

Answer 3

witch rose đúng

Answer 4

A2 = 8 + 2 16 - 10 - 2 ^5 + 4 -10 +2 ^ 5 = 8 + 2 ^ 5 - 1 2

A2 = 8 +2^5 - 2 = 6 +2^5 = 5 +1

=>A= 1 +5

Answer 5

SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

Answer 6

Rose đúng