(n^3-3n-5n^2)+(n^2+3+2n^3)

To simplify the given expression, we need to combine like terms.<br /><br />$(n^{3}-3n-5n^{2})+(n^{2}+3+2n^{3})$<br /><br />First, let's group the like terms together:<br /><br />$(n^{3} + 2n^{3}) + (-5n^{2} + n^{2}) + (-3n) + 3$<br /><br />Now, we can combine the like terms:<br /><br />$(3n^{3}) + (-4n^{2}) + (-3n) + 3$<br /><br />So, the simplified expression is:<br /><br />$3n^{3} - 4n^{2} - 3n + 3$