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

Simplification 

If a=x+y, b=x-y, c=x+2y, then $$ {a^2+b^2+c^2}-ab-bc-ca $$ is

If x = 2 then the value of $$ x^3 + 27x^2 + 243x + 631$$ is:

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

If p=99, then the value of p(p²+3p+3) will be

If a\b + b\a =1, then the value of a³+b³ will be 

Given that 10^0.48 = x, 10^0.70 = y and x² = y², then the value of z is close to