Question

If x+5 is a factor x^2+kx+5 then find the value of k please

Answer 1

zero of x+5= -5
p(x)= x²+kx+5
we know that x+5 is a factor of p(x)
so,  p(x)= x²+kx+5
        p(-5)= (-5)² +k(-5)+5=0
                           25-5k+5=0
                              30-5k=0
                                 -5k=-30
                                     k=6

Answer 2

Since x+5 is a factor of x^2+kx+5,
x^2+kx+5 = 0 (for x = -5)
=> (-5)^2 - 5k + 5 = 0
=> - 5k = - 30
=> k = 6
Therefore, k = 6