Question 1128287

 Consider the following.
x3 − kx2 + 2kx − 18
Find the value of k such that x − 3 is a factor of the above.
<pre>Set the expression equal to 0, as follows: {{{matrix(1,3, x^3 - kx^2 + 2kx - 18, "=", 0)}}}
One factor: x - 3 signifies that 1 of its roots is 3.
All you have to do is substitute 3 for x, and you'll see that k = 3.
That's all! Nothing MORE, nothing LESS!!