I am going to assume that the "8x2" is [tex]8x^2[/tex]. We need to combine like terms in this equation. Lets group them together first.
[tex]8x^2 - x^2 + 16x - 26x[/tex]
We combine like terms.
[tex]7x^2 - 10x[/tex]
Therefore, that is our final answer.