Answer: [tex]2x^4+2x+10[/tex]
Step-by-step explanation:
You need to remember the mulplication of signs:
[tex](+)(+)=+\\(-)(-)=+\\(-)(+)=-[/tex]
Knowing this, you can distributive the negative sign. Then you get:
[tex](-7x- 5x^4 + 5) - (-7x^4 - 5 - 9x)=-7x- 5x^4 + 5 +7x^4 + 5 + 9x[/tex]
Now you need to add the like terms. Then:
[tex]=2x+2x^4+10[/tex]
Finally, you can order the polynomial obtained in descending order. Therefore, the answer is:
[tex]=2x^4+2x+10[/tex]
