TÍNH:\(S=\dfrac{a}{a+b+c}+\dfrac{a+b+c}{a}+\dfrac{b}{a+b+c}+\dfrac{a+b+c}{b}+\dfrac{c}{a+b+c}+\dfrac{a+b+c}{c}-\dfrac{a}{b}-\dfrac{a}{c}-\dfrac{b}{a}-\dfrac{b}{c}-\dfrac{c}{a}-\dfrac{c}{b}\)

CHO xyz=1. TÍNH \(E=\left(x+\dfrac{1}{x}\right)^2+\left(y+\dfrac{1}{y}\right)^2+\left(z+\dfrac{1}{z}\right)^2-\left(x+\dfrac{1}{x}\right)\left(x+\dfrac{1}{y}\right)\left(z+\dfrac{1}{z}\right)\)