If (2 to the x) - (2 to the (x-2)) = 3 (2 to the 10), what is the value of x?  Options:
A) 9	B) 11	C) 13	D) 12	E) 17

Rationale: "( 2 to the power x ) - ( 2 to the power ( x - 2 ) ) = 3 ( 2 to the power 10 ) 2 ^ x - 2 ^ ( x - 2 ) = 3 . 2 ^ 10 hence x = 12 . answer is d"
Answer: D