Find the value of k if \(\frac{5 + 2r}{(r + 1)(r - 2)}\) expressed in partial fraction is \(\frac{k}{r - 2}\) + \(\frac{L}{r + 1}\) where K and L are constants

Find the value of k if \(\frac{5 + 2r}{(r + 1)(r - 2)}\) expressed in partial fraction is \(\frac{k}{r - 2}\) + \(\frac{L}{r + 1}\) where K and L are constants

A 3
B 2
C 1
D -1

jamb 1997 mathematics

The correct answer is A. 3

5 + 2r = k(r + 1) + L(r - 2)

but r - 2 = 0 and r = 2

9 = 3k

k = 3

Previous question Next question