Does the following # represent y as a function of x?

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

Amovie streaming service charges it’s customers $15 a month. martina has $98 saved up. will she have any money left over if she pays for the maximum amount of months she can afford? explain.

What expression is equivalent to log3(x+4)