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
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