If a² + b² + c² = 16, x² + y² + z² = 25 and ax + by + cz = 20,

then the value of a+b+c/x+y+z

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 are

If (x-1/x)² = 3, then the value of x⁶ + 1/x⁶ equals

If x = √5+1/√5-1 and y = √5-1/√5+1 , the value

of x²+xy+y²/x²-xy+y² is

If x² + y²+ 2x + 1 = 0, then the value of x³¹ + y³⁵ is

If a+b+c = 0 then the value of 

1/(a+b)(b+c) + 1/(b+c)(c+a) + 1/(c+a)(a+b) is