Question

How do you add `(3x-4x^2+8x^3)+(-6x+2x^4-5x^2)`?

Answer 1

You can get rid of the brackets:
`3x-4x^2+8x^3-6x+2x^4-5x^2=`
Now you can add terms with the same litteral part (for example `x^2` with another `x^2`) according to their value with sign:
`3x-6x-4x^2-5x^2+8x^3+2x^4=`
`-3x-9x^2+8x^3+2x^4`
or in descending order:
`2x^4+8x^3-9x^2-3x`