Question

a
$(a \div bc + b \div ca + c \div ab) {?}^{4}$

Answer 1

$\frac{a}{bc} + \frac{b}{ca} + \frac{c}{ab} \\ = \frac{c {a}^{2} + {b}^{2} c }{ab {c}^{2} } + \frac{c}{ab} \\ = \frac{ {a}^{3} bc + a {b}^{3} c + ab {c}^{3} }{ {a}^{2} {b}^{2} {c}^{2} } \\ = \frac{abc( {a}^{2} + {b}^{2} + {c}^{2} ) }{ {a}^{2} {b}^{2} {c}^{2} } \\ = \frac{ {a}^{2} + {b}^{2} + {c}^{2} }{abc}$