First, multiply the two terms in parenthesis. To multiply these two terms you multiply each individual term in the left parenthesis by each individual term in the right parenthesis.
3x(color(red)(3) - color(red)(x))(color(blue)(2) + color(blue)(y))3x(3−x)(2+y) becomes:
3x((color(red)(3) xx color(blue)(2)) + (color(red)(3) xx color(blue)(y)) - (color(red)(x) xx color(blue)(2)) - (color(red)(x) xx color(blue)(y)))3x((3×2)+(3×y)−(x×2)−(x×y))
3x((6 + 3y - 2x - xy)3x((6+3y−2x−xy)
Next, we can multiply each term within the parenthesis by the term outside the parenthesis:
color(red)(3x)((6 + 3y - 2x - xy)3x((6+3y−2x−xy)
(color(red)(3x xx 6) + (color(red)(3x xx 3y) - (color(red)(3x xx 2x) - (color(red)(3x xx xy)(3x×6+(3x×3y−(3x×2x−(3x×xy
18x + 9xy - 6x^2 - 3x^2y)18x+9xy−6x2−3x2y)
We can now put the terms in standard order:
-6x^2 - 3x^2y + 18x + 9xy)−6x2−3x2y+18x+9xy)