SOLUTION: Hi, could you plis show me the working out of the equation below (5x-2y) (x^2-3xy+y^2)-3(x-y) (x^2+y^2)

Algebra ->  Expressions -> SOLUTION: Hi, could you plis show me the working out of the equation below (5x-2y) (x^2-3xy+y^2)-3(x-y) (x^2+y^2)      Log On


   

Question 980473: Hi, could you plis show me the working out of the equation below
(5x-2y) (x^2-3xy+y^2)-3(x-y) (x^2+y^2)
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
%285x-2y%29+%28x%5E2-3xy%2By%5E2%29-3%28x-y%29+%28x%5E2%2By%5E2%29

Distributive Property should be used for the polynomial products, but once that is learned
then use of a lattice approach will often be more comfortable to get each partial product term.
Here will use the Distributive Property to start.

5x%2Ax%5E2-15x%2Axy%2B5xy%5E2-2x%5E2y%2B6xy%2Ay-3%28x%5E3%2Bxy%5E2-x%5E2%2Ay-y%5E3%29
5x%5E3-15x%5E2y%2B5xy%5E2-2x%5E2y%2B6xy%5E2-3x%5E3-3xy%5E2-3x%5E2y-3y%5E3
Some people can combine like-terms in their head as they go, and some cannot...
5x%5E3-3x%5E3-15x%5E2y-2x%5E2y-3x%5E2y%2B5xy%5E2%2B6xy%5E2-3xy%5E2-3y%5E3
Check to be sure that the same count of terms is there as in the previous step before actually
combining those like-terms.

2x%5E3-20x%5E2y%2B8xy%5E2-3y%5E3-------The result