Question

simplify (3x^2-4x+2)+(9x^3-5x-3)+(4x-8x^3)

Answer 1

collect the like terms, remove the brackets

\[9x^3 - 8x^3 + 3x^2 -4x -5x + 4x + 2 - 3\]

or
\[(9 - 8)x^3 + 3x^2 +(-4 -5+4)x +(2 - 3)\]

now just simplify

Answer 2

\[(3x^2-4x+2)+(9x^3-5x-3)+(4x-8x^3)\]
All you need to do is combine like terms. So combine all x^3 terms, all x^2 terms, all x terms and all coefficients.
You should end up with\[x^3+3x^2-5x-1\]