Mathematics
katkit25:

How do I add the opposite of (9x^2-4x+8)-(12x^2-6x-3) and (x-2x^3+8-7x^2)-(8+5x-3x^3)

What do you mean by 'opposite'

For adding these I think you just line up the like terms So x^2 can only be added with other x^2, x added with other x, and constants added with other constants (ex: 3 + 5).

katkit25:

I knnow hhow to solve it But i have no clues how to add the oppisite

Nnesha:

$\rm (9x^2-4x+8) \large \color{red}{-}(12x^2-6x-3)$ which is same as $\rm (9x^2-4x+8) \large \color{red}{-1}(12x^2-6x-3)$ 1st) distribute negative 1 2nd) combine like terms if the signs are opposite you will subtract.