By how much does the larger root of the equation 2a^2+5a = 12 exceed the smaller root? Choose the correct answer:
A) 5 / 2  B) 10 / 3  C) 7 / 2  D) 14 / 3  E) 11 / 2

Rationale: for 2 a ^ 2 + 5 a = 12 roots are [ - 5 + sqrt ( 25 + 96 ) ] / 4 or [ - 5 - sqrt ( 25 + 96 ) ] / 4 = 1.5 or - 4 hence larger root 1.5 is 1.5 - ( - 4 ) = 5.5 = 11 / 2 greater than smaller root ( - 4 ) . hence option ( e ) .
Answer: E