某种商品,每售出一件可得利润X元

1个回答

  • XY =12000

    (X - 0.3)(Y+5000) = 12000 + 1500

    XY=12000

    XY + 5000X - 0.3Y - 1500=12000 + 1500 5000X - 0.3Y = 3000

    5000 * 12000 - 0.3 Y² =3000Y

    3Y² +3000Y - 600000000=0

    Y² +1000Y - 200000000=0

    (Y +20000)(Y - 10000)=0

    Y=10000件

    X=12000 ÷ 10000 =1.2元