What are the roots of the function f(x)= (x^2-5x+4)/(x-4) ?

The roots of a function are the values of x at which f(x) =
0

f(x) = (x^2 - 5x + 4)/(x - 4) =
0

=> (x^2 - 5x + 4)/(x - 4) =
0

=> (x^2 - 4x - x + 4)/(x - 4) =
0

=> (x(x - 4) - 1(x - 4))/(x - 4) =
0

=> (x - 1)(x - 4)/(x - 4) =
0

=> (x - 1) = 0

=> x =
1

We get x = 1. At x = 4 the function is not
defined.

The root of the function is x =
1.