Question

factorise: x^3 - 23x^2 + 142x - 120  using long division and factor theorem

Answer 1

x3 - 23x2 +142x -120

Note that putting x=1 the value of the expression becomes zero.

Thus by the factor theorem (x-1) is a factor of the given polynomial.

The polynomial is a 3 degree polynomial and hence has 3 factors.

To get the other 2 factors divide the given polynomial by (x-1) and factorize the 2 degree polynomial obtained by middle term splitting.

The final answer that you will get will be (x-1)(x-10)(x-12)

Sub x=something first until f(x) =0 

Example, let x=1, 
F (x)=1^3 -23^2 + 142 -120=0 
Now you know (x-1) is a factor. Do long division f (x)/ (x-1) get a polynomial and factorise it. You should be able to get (x-1)(x-10)(x-12)

Answer 2

Answer:

899

Step-by-step explanation: