`2x . (x-4)^2 - (x+5).(x-2).(x+2) + 2(x+5)^2 - (x-1)^2`
`= 2x . (x^2 - 2 . x . 4 + 4^2) - (x+5).(x^2 - 2^2) + 2 . (x^2 + 2 . x . 5 + 5^2) - (x^2 - 2 . x . 1 + 1^2)`
` = 2x . (x^2 - 8x + 16) - (x+5).(x^2 - 4) + 2 . (x^2 + 10x + 25) - (x^2 - 2x+1)`
` = (2x^3 - 16x^2 + 32x) - (x^3 - 4x + 5x^2 - 20) + (2x^2 + 20x + 50) - (x^2 - 2x+1)`
` = 2x^3 - 16x^2 + 32x - x^3 + 4x - 5x^2 + 20 + 2x^2 + 20x + 50 - x^2 + 2x - 1`
` = (2x^3 - x^3) + (-16x^2 - 5x^2 + 2x^2 - x^2) + (32x + 4x + 20x + 2x) + (20+50-1)`
` = x^3 - 20x^2 + 58x + 69`
