xy=15000 (1)
(Y-5)(X+100)=15000 (2)
由上述两式可得:
(Y-5)(X+100)=xy
即:xy+100y-5x-500=xy
100y-5x-500=0
20y-x-100=0
那么:x=20y-100 (3)
将(3)式代入(1)式得:
(20y-100)y=15000
y(y-5)=750
即y²-5y-750=0
(y-30)(y+25)=0
解得:{y=30,x=500或者:{y=-25,x=-600
xy=15000 (1)
(Y-5)(X+100)=15000 (2)
由上述两式可得:
(Y-5)(X+100)=xy
即:xy+100y-5x-500=xy
100y-5x-500=0
20y-x-100=0
那么:x=20y-100 (3)
将(3)式代入(1)式得:
(20y-100)y=15000
y(y-5)=750
即y²-5y-750=0
(y-30)(y+25)=0
解得:{y=30,x=500或者:{y=-25,x=-600