Question 89
Show that for all positive real numbers $a$, $b$, $c$:
$$
\frac{b c}{a^{2}+2 b c}+\frac{c a}{b^{2}+2 c a}+\frac{a b}{c^{2}+2 a b} \leqslant 1 \leqslant \frac{a^{2}}{a^{2}+2 b c}+\frac{b^{2}}{b^{2}+2 c a}+\frac{c^{2}}{c^{2}+2 a b}
$$
$$
\frac{b c}{a^{2}+2 b c}+\frac{c a}{b^{2}+2 c a}+\frac{a b}{c^{2}+2 a b} \leqslant 1 \leqslant \frac{a^{2}}{a^{2}+2 b c}+\frac{b^{2}}{b^{2}+2 c a}+\frac{c^{2}}{c^{2}+2 a b}
$$