Question

if x+2 is a factor of polynomial f(x)= x^2+3x+k , find k

Answer 1

Step-by-step explanation:

x+2=0

x=-2

(-2)²+(3(-2)+k=0

4-6+k=0

k=2 is the answer of this question

Answer 2

Answer:

as x+2 is a factor of x^2 + 3x + k, then f(-2) = 0

therefore f(-2) = (-2)^2 + 3(-2) + k = 0

=> f(-2) = 4 - 6 + k = 0

=> -2 + k = 0

=> -2 = -k

=> k = 2