Prove that the sum of three consecutive integers is divisible by 3

If using the method of completing the square to solve the quadratic equation x 2 + 16 x + 24 = 0 x 2 +16x+24=0, which number would have to be added to "complete the square"?

The measures of ? 1, ? 2, and ? 3 are 40%, 12.5%, and 25% of the sum of the angle measures of the quadrilateral. find the value of x.

Which equation is represented by the graph below?