Question : If $x+y+z=13,x^2+y^2+z^2=133$ and $x^3+y^3+z^3=847$, then the value of $\sqrt[3]{x y z}$ is:

Option 1: $8$

Option 2: $7$

Option 3: $-9$

Option 4: $-6$

Question : If $x^4+x^2 y^2+y^4=21$ and $x^2+xy+y^2=3$, then what is the value of $4xy $?
 

Option 1: –8

Option 2: 4

Option 3: –4

Option 4: 12

Question : If $\frac{x}{4 y}=\frac{3}{4}$ then, the value of $\frac{2 x+3 y}{x–2 y}$ is:

Option 1: 7

Option 2: 9

Option 3: 6

Option 4: 8

Question : If $x^2+8 y^2+12 y-4 x y+9=0$, then the value of $(7 x+8 y)$ is:

Option 1: –33

Option 2: 9

Option 3: 33

Option 4: –9

Question : If $x^4+y^4=x^2 y^2$, then the value of $x^6+y^6$ is:

Option 1: 2

Option 2: 0

Option 3: 1

Option 4: 3