Question

F(x)=x^3-x^2-26x+23, k=5 f(x)=?

Answer 1

f(x)=x^3-x^2-26x+23, k=5

Find the seros of the cubic equation

using a graphing tool

see the attached figure

please wait a minute

The zeros are -5, 1 and 5

so

f(x)=(x+5)(x+1)(x-5)

Find the product of (x+5)(x+1)

(x+5)(x+1)=x^2+x+5x+5

=(x^2+6x+5)

substitute

f(x)=(x-5)(x^2+6x+5)-7