The subtraction in (x-9)^2 makes the function shift to the right, adding would make it shift left! Adding numbers to the equation would make the function go up, and subtracting would make it go down. Hope this helps :)
There are 30 dozen, a dozen means twelve. 30 times 12 is 360. There are 360 pairs of gloves. A pair means 2. 360 pairs times 2 gloves in a pair equals 720.