先积x,∫∫ (x²+y²-y)dxdy=∫[0--->2]dy∫[y/2--->y] (x²+y²-y)dx=∫[0--->2] (1/3x³+xy²-xy) |[y/2--->y]dy=∫[0--->2] (1/3y³+y³-y²-(1/3)(y/2)³-y³/2+y²/2) dy=∫[0--->2] [(19/24)y³-(1/2)y²] dy=[(19/96)y⁴-(1/6)y³] |[0--->2]=11/6