If (2 to the x) - (2 to the (x-2)) = 3 (2 to the 11), what is the value of x?  Options.
A) 9 B) 11 C) 13 D) 15 E) 17

Rationale: "( 2 to the power x ) - ( 2 to the power ( x - 2 ) ) = 3 ( 2 to the power 11 ) 2 ^ x - 2 ^ ( x - 2 ) = 3 . 2 ^ 11 hence x = 13 . answer is c"
Answer: C