Question : A complete factorisation of $(x^4+64)$ is:

Option 1: $(x^2+8)^2$

Option 2: $(x^2+8)$$(x^2-8)$

Option 3: $(x^2-4x+8)(x^2-4x-8)$

Option 4: $(x^2+4x+8)$$(x^2-4x+8)$

Question : If $x$,$y$ and $z$ are real numbers such that $(x-3)^2+(y-4)^2+(z-5)^2=0$, then $(x+y+z)$ is equal to:

Option 1: –12

Option 2: 0

Option 3: 8

Option 4: 12

Question : If $x=\sqrt{–\sqrt{3}+\sqrt{3+8 \sqrt{7+4 \sqrt{3}}}}$ where $x > 0$, then the value of $x$ is equal to:

Option 1: 3

Option 2: 4

Option 3: 1

Option 4: 2

Question : If $x+y=1+xy$, then $x^3+y^3-x^3y^3$ is equal to:

Option 1: 0

Option 2: 1

Option 3: –1

Option 4: 2

Question : If $(x-5)^2+(y-2)^2+(z-9)^2=0$, then value of $(x+y-z)$ is:

Option 1: 16

Option 2: –1

Option 3: –2

Option 4: 12