If pq+qr+rp=0 then find the value of $$ {p^{2}\over {p^{2}-qr}}+{q^{2}\over {q^{2}-rp}}+{r^{2}\over {r^{2}-pq}}$$

If 0.13 x p² = 13, then p is equal to

If a-b=1 and a³-b³=61, then the value of ab will be 

What will be the value of x³+y³+z³-3xyz when x+y+z=9 and x²+y²+z²=31?

 If x+y=14: x³+y³=1064, then the value of (x-y)² is:

If a+b+c=15 and a²+b²+c²=83 then the value of a³+b³+c³-3abc

If $${144\over0.144}={14.4\over x}$$, then the value of x is

If  $$ \ {xy\over x+y}= a, $$ $${xz\over x+z}=b $$ and $$ {yz\over y+z} =c $$  where a, b, c are all non – zero numbers, then x equals to