Question

if -4 is a root of quadratic equation x^2+px-4=0 and the equation 2x^2+px+k=0 has equal roots find k

Answer 1

if x = –4 , 16 + p4 -4= 0
-4p = 4-16
-4p = -12
p = 3
32-12+k=0
k = 20