(x-3)^2-(x+3)(x-3)при x=-0,1
x²-3×1×x+3²-(x²-3x+3x-9) | -3x+3x=0
x²-3x+9-(x²-9) | x²-x²=0
-3x | 9-9=0
при x=0,1 => -3×0,1=0,3