х⁴+6х³+15х²+20х+12 = x⁴ + 2x³ + 4x³ + 8x² + 7x² + 14x + 6x + 12 = x³(x+2) + 4x²(x+2) + 7x(x+2) + 6(x+2) = (x+2)(x³+4x²+7x+6) = (x+2)(x³ + 2x² + 2x² + 4x + 3x + 6) = (x+2)*(x²(x+2) + 2x(x+2) + 3(x+2)) = (x+2)²(x² + 2x + 3)
х⁴+6х³+15х²+20х+12 = x⁴ + 2x³ + 4x³ + 8x² + 7x² + 14x + 6x + 12 = x³(x+2) + 4x²(x+2) + 7x(x+2) + 6(x+2) = (x+2)(x³+4x²+7x+6) = (x+2)(x³ + 2x² + 2x² + 4x + 3x + 6) = (x+2)*(x²(x+2) + 2x(x+2) + 3(x+2)) = (x+2)²(x² + 2x + 3)