Three positive numbers are in the ratio of 11 : 12 : 15. If the sum of the squares of those numbers is 1960, then the sum of the numbers is

$$ {x+{1\over{x}}}$$, then the value of $$ {x^2}+{1\over{x^2}}$$ is

If a = 2.234, b = 3.121 and c = –5.355, then the value of $$ a^3 + b^3 + c^3 – 3abc$$ is

If a-6b = 3 then the value of a³-216b³-54ab is : 

x = y = 333 and z = 334, then value of x³ + y³ + z³ – 3xyz is 

If $$ {(x+{1 \over{x}})^{2}}=3$$, the value of of $$  {x^{206}+x^{200}+x^{90}+x^{84}+x^{18}+x^{12}+x^{6}+1}$$

If $$ \sqrt {x^2+y^2}=25$$, and y=2x, find x. 

If x⁴+2x³+ax²+bx+9 is a perfect square where a and b are positive real numbers, then the value of a and b