Negative Monomial Times a Trinomial

Give an example of using the distributive property for a negative monomial times a trinomial with different signs on the terms [for example: -3x(2xy + 3y – 2x)] and show each step of the distribution. Why do you think many students make sign errors on this type of problem? What would be your advice to a student who has trouble with the signs?

* Response to question must be 75 to 150 words or more if need be. Cite outside sources if any are used.