I’ll give brainliest help a girl out

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

How do you find the circumfrance of a circle?

Given the quadratic function f(x)=3x^2-24x+49 a. use “completing the squares” to convert the quadratic function into vertex form b. state the vertex c. find the x and y intercepts d. graph the function