Answer:
[tex]\large\boxed{-x^5+3x^4+16x^3+7x^2-3x+6}[/tex]
Step-by-step explanation:
[tex](x^5 - 4x^4 + 7x^3 + 8)+(9x^3+ 7x^2 - 10)+(-2x^5 + 7x^4 - 3x + 8)\\\\=x^5 - 4x^4 + 7x^3 + 8+9x^3+ 7x^2 - 10-2x^5 + 7x^4 - 3x + 8\\\\\text{combine like terms}\\\\=(x^5-2x^5)+(-4x^4+7x^4)+(7x^3+9x^3)+7x^2-3x+(8-10+8)\\\\=-x^5+3x^4+16x^3+7x^2-3x+6[/tex]
