If $$ {x+{9\over x}=6}$$  then find the value of $$ {x^{2}+{1\over x^{3}}}$$

If p³ – q³ = (p-q)[(p-q)²+xpq)] then the value of x is

If $$ ({x+y\over z})=2$$ , then what is the value of $$ [{ {y\over {y-z}}}] +[{ {x\over {x-z}}}]$$.

If $$ {(x-5)^{2} +{(y-2)^{2}}+{(z-9)^{2}=0}}$$ then what is the value of (x+y-z)?

If 4x² + y² = 40 and xy = 6, then find the value of 2x + y.

 If $${\sqrt{7-2}\over\sqrt{7+2}}=a\sqrt{7}+b$$, then the value of a is : 

If $$ {x^2} -4x-1 $$ then the value of $$ {{x^6} -{x^4}+{x^2}-1}\over {x^3}$$ will be

If $$ {x+{1\over x}=7}$$ then $$ {x^{2}+{1\over {x^{2}}}=?}$$