we can ad like terms basically x^2 can be added to 2x^2 but not 3 or 2x^4 so we have (x^3+x^2)+(2x^3-5x^2) using associative and commutative property remove the parenthaseese x^3+x^2+2x^3-5x^2 and move them around so group the like terms 1x^3+2x^3+1x^2-5x^2 add 3x^3-4x^2 tada
