Answer :
(-3x^2+2x-3) - (x^3-x^2+3x) distribute the negative
-3x^2+2x-3-x^3+x^2-3x
And than add like terms
-x^3-2x^2-x-3
(x³ - x² + 3x) - (-3x² + 2x - 3)
(x³ - x² + 3x² + 3x - 2x - 3)
x³ + 2x² + x - 3
(x³ - x² + 3x² + 3x - 2x - 3)
x³ + 2x² + x - 3