Question

find the value of k if (x-5) is a factor of x^3 + 3x^2 + kx +5​

Answer 1

Step-by-step explanation:

here X=5

so put value of X in this equation

125+75+5k+5=0

5k=-205

k=-41

Answer 2

Here,

p(x) = x³+3x²+Kx+5

g(x) = x-5

It is given that g(x) is a factor of p(x) , and we have to find the value of k.

So , x-5 is a factor then zero :

x-5 = 0

x = 5

Put x = 5 in p(x) to find the value of k :

x³+3x²+Kx+5 = 0

(5)³+3(5)²+k(5)+5 = 0

125 + 75 +5k +5 = 0

205+5k = 0

5k = -205

k = -205/5 = -41

The required value of k = -41.