The Brainliest Answer!

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
When adding polynomials, you may only combine similar terms. Similar terms are constants(without variables) and those with same variables raised to the same power.

For 5x³ + 9 -4x² +5 , there are no similar terms except for the constants. 
Therefore, 5x³ -4x² +14 is its simplest form. 

Note that we usually arrange terms in decreasing degree.
2 4 2