The answer is
B) Twice the original number. Why? because you said.
Answer: 
Not a factor because there is a remainder.
Step-by-step explanation:
Let's use synthetic division to solve this..
-1 ║ 2 | 4 | -2 | -8
║ | -2| -2 | 4
║ 2 | 2| -4 | -4

PS: if anyone knows a better way to do a synthetic division chart please let me know.
Answer: D
Step-by-step explanation: By using SOH for sin A, 'S' being sin, 'O' being opposite side of angle A and 'H' being the hypotenuse which is the longest part of the triangle you would find that 15 is opposite from Sin A and 17 the hypotenuse, 15/17.
For cos A you would use CAH, C= cos, A which is the adjacent of the triangle located next to angel A which is 8, and H= hypotenuse (also note that the hypotenuse never changes even if the angle may be different) CAH would be cos A = 8/17
X-9=12
x-9+9=12+9
You need to add 9 to each side of the equation.
x=21