If a - b = 3 and a^2 + b^2 = 27, find the value of ab.  Pick:
A) 12	B) 15	C) 10	D) 18	E) 9
2ab = (a^2 + b^2) - (a - b)^2   = 27 - 9= 
<gadget id="calculator">27 - 9</gadget>
<output>18</output>
18   ab= 9.   Answer is 9.
<result>E</result>
If a - b = 3 and a^2 + b^2 = 27, find the value of ab.