Question 33481
{{{ (5x^3+4x-x^2) - (2x-3x^2+5x^3) }}}
First ... order each piece in DESENDING powers
{{{ (5x^3-x^2+4x) - (5x^3-3x^2+2x) }}}
Distribute the negative across the second quantity ... in other words, change the signs.
{{{ 5x^3 -x^2 +4x -5x^3 +3x^2 -2x }}}
5x^3 cancels
{{{ -x^2 +4x +3x^2 -2x }}}
Add the x^2
{{{ 2x^2 +4x -2x }}}
add the x
{{{ 2x^2 +2x }}}
DONE