If you treat (x+5) as a single value and (x-2) as the values of x and +2, you can distribute (x+5) to x and +2: ( (x-5)*x + (x-5)*2 ). Then you can treat x-5 as the values of x and -5 and distribute those to the numbers next to them: (×^2 - 5x) + (2x - 10). This results in x^2 -3x - 10.
