Simplifying the rational expression "-12x^3/x^3-5x^4" involves cancelling out the terms or variables that are common or present in each term. For this example, the common term is "x^3". So for the first step, bring out all of the x^3 terms. This gives:
--> -12x^3/x^3(1-5x)
Since this is a fraction, the x^3 can be cancelled out from the numerator and denominator.
final answer --> -12/(1-5x)
