>>265
×1/4x^4 + 2x^3 + 6x^2 + 8x
○1/4x^4 + 2x^3 + 6x^2 + 8x+C

×1/4x^4 + 2x^3 + 6x^2 + 8x +16
○1/4x^4 + 2x^3 + 6x^2 + 8x +16+C'

C-C' = 16