If x - y = 6 and xy = 40, then  find $$ {x^2+y^2}$$

If x = b+c -2a, y=c+a-2b, z=a+b-2c, then the value of x²+y²-z²+2xy is : 

If $$ x={\sqrt3\over{2}}$$ then the value of $$ \sqrt{1+x}-\sqrt{1-x}$$ will be

If (a+b)=16 and a³+b³=1456, then what is the value of ab?

If $$ {x^{2}+3{x}+1=0}$$, then the value of $$ {x^{3}+{1\over {x^{3}}}}$$

Given k = -3. Find the value of $$ {k^3+3k}$$. 

If a²+b²+c² = 2(a – b – c) – 3 then the value of 4a – 3b + 5c is 

If x, y are two positive real number and  $$x^{1/3}=y^{1/4}$$, then which of the following relations is true?