Chứng minh rằng:

\(\frac{a^2+b^2}{\left(a-b\right)^2}+\frac{b^2+c^2}{\left(b-c\right)^2}+\frac{c^2+a^2}{\left(c-a\right)^2}\ge\frac{5}{2}\)

Chứng minh rằng:

\(\frac{\left(a+b\right)^2}{\left(a-b\right)^2}+\frac{\left(b+c\right)^2}{\left(b-c\right)^2}+\frac{\left(c+a\right)^2}{\left(c-a\right)^2}\ge2\)

Chứng minh rằng:

\(\frac{a-b}{1+ab}+\frac{b-c}{1+bc}+\frac{c-a}{1+ca}=\frac{a-b}{1+ab}.\frac{b-c}{b+c}.\frac{c-a}{c+a}\)

Cho \(a,b,c\ne0\) thỏa mãn: \(a-b-c=0\). Tính:

\(D=\frac{1}{a^2+b^2-c^2}+\frac{1}{b^2+c^2-a^2}+\frac{1}{c^2+a^2-b^2}\)

Chứng minh BĐT:

\(\left|x-1\right|+\left|3x-4\right|+\left|x-3\right|\ge2\)

Help!!!Ai đúng mk tick!!!Thanks