Question : Simplify the expression:
$(2x+13-y)(2x-13-y)$

Option 1: $4x^2-y^2-4xy-169$

Option 2: $4x^2+y^2+4xy-169$

Option 3: $4x^2+y^2-4xy-169$

Option 4: $4x^2+y^2-4xy+169$

Question : If $4x^2+y^2 = 40$ and $xy=6$, then the value of $2x-y$ is:

Option 1: 1

Option 2: 3

Option 3: 4

Option 4: 2

Question : If $\sin^4x + \sin^2x = 1$, then what is the value of $\cot^4x+ \cot^2x$?

Option 1: –2

Option 2: 2

Option 3: –1

Option 4: 1

Question : If $2x-3(4-2x)<4x-5<4x+\frac{2x}{3}$, then $x$ can take which of the following values?

Option 1: 2

Option 2: 8

Option 3: 0

Option 4: –8

Question : If $2x-3(4-2x)<4x-5<4x+\frac{2x}{3}$, then $x$ can take which of the following values?

Option 1: 2

Option 2: 8

Option 3: 0

Option 4: –8