first we will compute the h+k and then multiply the result by 2.
To add polynomials, we add terms whose variables are alike, for example:
we add the coefficients of x^2 together, the coefficients of x together and so on.
Therefore:
h + k = x^2 + 1 + x - 2 = x^2+x-1
Now, we will multiply this answer by 2 to get the final answer:
2(h+k) = 2(x^2+x-1) = 2x^2 + 2x -2