Question

if X + K is the gcd of x square - 2 x minus 15 and x cube + 27 find the value of k

Answer 1

 (x+k) means x=-k 

 x2-2x-15

(-k)2-2(-k)-15=0

k2+2k-15=0

k2+5k-3k-15=0

k(k+5)-3(k+5)

(k-3) (k+5)

k=3, -5

x3+a

(-k)3+a

a=k

a = 27 , -125

Answer 2

Answer:

3,-5

Step-by-step explanation:

(x+k) means x=-k

x2-2x-15

(-k)2-2(-k)-15=0

k2+2k-15=0

k2+5k-3k-15=0

k(k+5)-3(k+5)

(k-3) (k+5)

k=3, -5