[Euler-Fermat]

2. $(a+b+c)(\frac{1}{a+b}+\frac{1}{b+c}+\frac{1}{c+a}) = \frac{11x13}{17} $
$\frac{c}{a+b}+\frac{a}{b+c}+\frac{b}{c+a} = \frac{143}{17} -3 = \frac{92}{17}$