We are given the following rational expression:
[tex]\frac{x^4-4x^3-6x^2+20x-75}{x^2-2x+5}[/tex]
For calculation A we notice that when performing an algebraic division the result was:
[tex]x^2-2x-15[/tex]
And the remainder was zero. This means that the numerator can be factored as:
[tex]x^4-4x^3-6x^2+20x-75=(x^2-2x+5)(x^2-2x-15)[/tex]
Therefore, calculation A is accurate because it factors the numerator and reveals that the denominator is a factor.
In the case of calculation B we notice that there is an error in the second part of the division. When "2x" was multiplied by the dividend the result is:
[tex]2x(x^2-2x+5)=2x^3-4x^2+10x[/tex]
But in the operation the result was:
[tex]2x^3-4x^2-10x[/tex]
Therefore, Calculation B is inaccurate, because it incorrectly factors the numerator.