You must first transform into a multiplication and then factor to see what you can eliminate.
Explanation:
To transform a fractional division into a multiplication, you have to inverse the numerator and the denominator of the second fraction.
x2−4x3+7x2×x2+4x−21x3−x2−6x
(x+2)(x−2)x2(x+7)×(x+7)(x−3)x(x−3)(x+2)
Since aa=1,a= all real numbers, we can proceed by eliminating factors that appear in the numerator and the denominator.
We are left with x−2/x^3
