WILL GIVE BRAINLIEST!!!

Answer:
We have been given [tex](4x^3-6)+(5x^3+3)[/tex]
We need to add or subtract so since here we have sign of addition so we will add the expression in separate parenthesis.
[tex]4x^3-6+5x^3+3[/tex]
[tex]9x^3-3[/tex]
Taking common factor out which is 3.
[tex]3(3x^3-1)[/tex]
Similarly, we have been given:[tex](20v^2-9v^3)-(7v^3-10v^4-14v^2)[/tex]
Here we will subtract being minus in between.
[tex]20v^2-9v^3-7v^3+10v^4+14v^2[/tex]
[tex]34v^2-16v^3+10v^4[/tex]