Distributive Property

I am having problems understanding how to distribute.
3(4 + 5) = 3(9) or 3(4) + 3(5) ok easy enough. Now how i use the distributive property when using variables? For instance. 4u²v(u-v) If i dustribute i end up getting 4u³v - 4u²v² Now do i leave this like this? And what do i do if i want to not distribute and do whats inside the ()?4u²v(u-v) == -4v³v² :confused:

no u cant do anything after that.. because u can only combine like terms.. and a term is defined by the set of variables and their exponents.. for example. 4x-3y will not work x and y are not the same term... 4x^3 isnt the same at 4x^2 b/c the exponents are different.. and no.. u cannot do whats in the ()'s first b/c u cannot combine like terms.. as i just said.. the only time u can combine unlike terms is when multiplying... for example 5xy^2 * 2xu=10x^2y^2u

Ok i got it. Thanks for the help. :)

4u²v(u - v) - (uv³ + u²v²)

4u³v - 4 u²v² - uv³ - u²v²

4u³v - 5u²v² - uv³

i dont follow you from your second step to you third step

Just combining like terms. :)

ok.. sorry.. i wuz a lil slow that day...lol