Question 91805
{{{4x^3 + x - 3x^2}}} - ({{{4x - 2x^2+4x^3}}})

= {{{4x^3 + x - 3x^2 - 4x + 2x^2 - 4x^3}}}

combine like terms : {{{4x^3}}} canceled.

we get {{{-x^2 - 3x}}}

and that's the answer