biết a+b+c=0, hãy rút gọn:

\(\dfrac{a^2}{a^2-b^2-c^2}+\dfrac{b^2}{b^2-a^2-c^2}+\dfrac{c^2}{c^2-a^2-b^2}\)

\(\dfrac{1}{b^2+c^2-a^2}+\dfrac{1}{c^2+a^2-b^2}+\dfrac{1}{a^2+b^2-c^2}\)

tìm min \(\dfrac{x+16}{\sqrt{x}+3}\)

`1/(x^2 +x+1)^2 + 1/(x^2 +x+2)^2 = 13/36`

\(\dfrac{1}{\sqrt{5}+\sqrt{3}}-\dfrac{1}{\sqrt{5}-\sqrt{3}}\)

\(\dfrac{\sqrt{4-2\sqrt{3}}}{\sqrt{6}-\sqrt{2}}\)

\(\sqrt{127-48\sqrt{7}}-\sqrt{127+48\sqrt{7}}\)

\(\dfrac{\sqrt{10}+\sqrt{6}}{2\sqrt{5}+\sqrt{12}}\)