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 $$ {4p\over{{p^2}}-4p+4}={1\over8}$$, p≠0 then the value of $$ {p+{4\over p}}$$

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

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

If a + a²+a³-1=0, then what is the value of a³ +(1/a)?

If $$ {8x\over{2x^{2}+7x-2}}=1, x>0,$$ then what is the value of of $$ {x^{3}+{1\over x^{3}}}$$ ?

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