A binary operation * on the set of rational numbers is defined as (x ast y = frac{x^2 – y^2}{2xy}). Find (-5 ast 3)
- A.
(frac{-8}{15}) - B.
(frac{8}{15}) - C.
(frac{17}{15}) - D.
(frac{-17}{15})
Correct Answer: Option A
Explanation
(x ast y = frac{x^2 – y^2}{2xy}\
=frac{(x+y)(x-y)}{2xy}\
-5 ast 3 =frac{(-5+3)(-5-3)}{2(-5times3)}\
=frac{-2 times -8}{2(-5times3)}\
=frac{-8}{15})