We are given the following expression:
[tex]\mleft(7x^4+2x^3\mright)-(-9x^4+5x^3)[/tex]To remove the parenthesis we will apply the distributive law on the right parenthesis:
[tex](7x^4+2x^3)-(-9x^4+5x^3)=7x^4+2x^3+9x^4-5x^3[/tex]Now, we associate like terms. This means the terms that have the same variable and that are elevated to the same exponent.
[tex]7x^4+2x^3+9x^4-5x^3=(7x^4+9x^4)+(2x^3-5x^3)[/tex]Now, we add like terms:
[tex](7x^4+9x^4)+(2x^3-5x^3)=16x^4-3x^3[/tex]Since we can't simplify any further this is the final answer.
