Adding and subtracting polynomials

Can you me find the missing length. i attached an image.

The number of 8th graders who responded to a poll of 6th grade and 8 th graders was one fourtg of the number of 6th graders whi responded if a total of 100 students responddd to the poll how many of the students responded were 6 th graders

Which zero pair could be added to the function f(x) = x2 + 12x + 6 so that the function can be written in vertex form? o 3, -3o 6,629,-936, 36