The standard form Ax^2 + Bx + C =0
A = k, B = 5, C =r
From the factors, the roots are 2, ½
The sum of roots = (2 + ½) =-5/2
Which is also equal to –B/A, -5/k
Therefore k = 2
The product of roots = 2(1/2) = 1
Which is also equal to C/A, C/2
Therefore C = 2