Question

what is the sum of the roots of the polynomial shown

Answer 1

Usually an eyeball problem. Just look at it and write down the answer.

Take a, and b - two Real Numbers
A Trinomial with these a and b as roots is (x-a)(x-b).
Multiplying out, (x-a)(x-b) = x^2 - (a+b)x + ab
Does one of those coefficients look like the sum of the roots?