Subtract 9 from 16 as an expression pls help

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

Through non-collinear points there is exactly one plane.

Type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar.a city water tank holds 20 gallons of water. a technician empties 25% of the tank. how many more gallons of water must be removed from thetank so that it has 5 of the water that it started with: the technician must removemore gallons of water for the tank to have 5 of the water that it started with.