Question

if x = 4 is a root of x2 - 9x + k = 0, find the value of k and hence find the other root

Answer 1

putting x= 4 in p (x)

p(4)= 16-36+k=0

k=20

Answer 2

Putting value of x=4

(4)²–9(4)+k=0

16–36+k=0

–20=–k

k=20