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

$3 x - 4 {x}^{2} + 8 {x}^{3} - 6 x + 2 {x}^{4} - 5 {x}^{2} =$
Now you can add terms with the same litteral part (for example ${x}^{2}$ with another ${x}^{2}$) according to their value with sign:
$3 x - 6 x - 4 {x}^{2} - 5 {x}^{2} + 8 {x}^{3} + 2 {x}^{4} =$
$- 3 x - 9 {x}^{2} + 8 {x}^{3} + 2 {x}^{4}$
$2 {x}^{4} + 8 {x}^{3} - 9 {x}^{2} - 3 x$