Question

六括号x减y括号的三次方加15括号y减x括号的平方减9括号y减x括号的三次方

Answer 1

6(x-y)^3+15(y-x)^2-9(y-x)^3

=6(x-y)^3+15(x-y)^2+9(x-y)^3

=15(x-y)^3+15(x-y)^2

=15(x-y+1)(x-y)^2