Write in Standard Form (12+8k^3+3k-4k^2)+(5k^3+15-k+2k^2)

$(12 + 8 k^{3} + 3 k - 4 k^{2}) + (5 k^{3} + 15 - k + 2 k^{2})$

To write a polynomial in standard form, simplify and then arrange the terms in descending order.

$a x^{2} + b x + c$

Add $12$ and $15$ .

$8 k^{3} + 3 k - 4 k^{2} + 5 k^{3} + 27 - k + 2 k^{2}$

Add $8 k^{3}$ and $5 k^{3}$ .

$13 k^{3} + 3 k - 4 k^{2} + 27 - k + 2 k^{2}$

Subtract $k$ from $3 k$ .

$13 k^{3} + 2 k - 4 k^{2} + 27 + 2 k^{2}$

Add $- 4 k^{2}$ and $2 k^{2}$ .

$13 k^{3} + 2 k - 2 k^{2} + 27$

Move $2 k$ .

$13 k^{3} - 2 k^{2} + 2 k + 27$