if $$x-{1\over 5},x≠0,$$ then what is the value of $${x^6+3x^3-1}\over x^6-8x^3-1$$=?

If x – y + z = 15, xyz = -216 and xz – xy – yz = 18, then the value of $$ {x^3}-{y^3}+{z^3}=$$

If a^2x+2=1, where a is a positive real number other than 1, then x is equal to 

$$ {a^2-b^2-2bc-c^2}\over{a^2+b^2+2ab-c^2}$$ is equal to

If $$p×q=p+q+{p\over q}$$, the value of 8 × 2  is : 

Two numbers x and y (x>y) such that their sum is equal to three times their difference. Then value of $$3xy\over 2(x^2-y^2$$ will be 

If $$ {a^{x}={(x+y+z)^{y}}}, a^{y}=(x+y+z)^{z}  and \ a^{z}=(x+y+z)^{x}$$ then the value of (x +y +z) is

 if $$\sqrt { 11- 3\sqrt { 8}}=a+b\sqrt { 2}$$, then what is the value of (2a+3b)?