Question

rút gọn bt

C=\(\sqrt{8+2\sqrt{7}}+\sqrt{8-2\sqrt{7}}\)

Answer 1

\(\sqrt{1+\left(\sqrt{7}\right)^2+2\sqrt{7}}+\sqrt{1+\left(\sqrt{7}\right)^2-2\sqrt{7}} =\sqrt{\left(1+\sqrt{7}\right)^2}+\sqrt{\left(1-\sqrt{7}\right)^2}=1+\sqrt{7}+1-\sqrt{7}=2\)

Answer 2

mình nhầm \(1+\sqrt{7}+\sqrt{7}-1=2\sqrt{7}\)

Answer 3

C = \(\sqrt{8+2\sqrt{7}}+\sqrt{8-2\sqrt{7}}\)

C = \(\sqrt{7+2\sqrt{7}+1}+\sqrt{7-2\sqrt{7}+1}\)

C = \(\sqrt{\left(\sqrt{7}+1\right)^2}+\sqrt{\left(\sqrt{7}-1\right)^2}\)

C = \(\sqrt{7}+1+\sqrt{7}-1\)

C = \(2\sqrt{7}\)