Question 74454
 s^2/r-s + r^2/s-r
s- r = -(r-s)
So the given expression is written as s^2/r-s - r^2/r-s
= (s^2 - r^2)/(r-s)

= (s+r)(s-r)/(r-s) [using a^2-b^2=(a+b)(a-b)]

= -(s+r)(r-s)/(r-s)

= -(s+r)





Good Luck!!!