Answer :
add like terms
I'm assuming that you forgot to put the parenthasees at the end
so exg
4x+8x=12x
2x^2+3x^2=5x^2
3x^2+3x^3=3x^2+3x^3
group like tems
6x^3+9x-8+5x-9x^2+7
6x^3-9x^2+14x-1
I'm assuming that you forgot to put the parenthasees at the end
so exg
4x+8x=12x
2x^2+3x^2=5x^2
3x^2+3x^3=3x^2+3x^3
group like tems
6x^3+9x-8+5x-9x^2+7
6x^3-9x^2+14x-1