Question

solve this..........

Answer 1

(a-b)³=a³-b³-3a²b+3ab²(using the formula)

p³(q-r)³+q³(r-p)³+r³(p-q)³ = p³(q³-r³-3q²r+3qr²)        +      q³(r³-p³-3r²p+3rp²)      +       r³(p³-q³-3p²q+3pq²)

= (p³q³-p³r³-3p³q²r+3p³qr²) + (q³r³-q³p³-3q³r²p+3q³rp²) + (r³p³-r³q³-3r³p²q+3r³pq²)

=p³q³-p³r³+q³r³-q³p³+r³p³-r³q³   -3(p³q²r+q³r²p+r³p²q) + 3(p³qr²+q³rp²+r³pq²)

=0-3pqr(p²q+q²r+r²p)+3pqr(p²r+q²p+qr²)

=3pqr(p²r+q²p+qr²-p²q-q²r-rp)