Mathematics

Problem

Which one of the following statements is always true if the quadratic polynomial

x^{2}+bx+k

can be written as

(x+r)(x+s)

with integers

r

and

s

? a)

r+s=-b

and

rs=k

r+s=k

and

rs=b

r+s=b

and

rs=k

r+s=b

and

rs=-k