If a-b= 3 and a^2+b^2=29, find the value of ab Answers:	A) 10	B) 12	C) 15	D) 18	E) 19

Rationale: "2 ab = ( a ^ 2 + b ^ 2 ) - ( a - b ) ^ 2 = 29 - 9 = 20 = > ab = 10 . answer : a"
Answer: A