Question 861678
Draw a picture of this.  You should be able to see that the outside area minus the inside area is the frame area.  All three of these areas are square-based.  The inside frame dimensions are the square painting area.  


In symbols, {{{(3x-2)(3x-2)-(x+7)(x+7)}}} is the frame area.
{{{9x^2-6x-6x+4-(x^2+14x+49)}}}
{{{highlight(8x^2-26x-45)}}}