{X-Y=630 {X(1+20%)+Y(1-10%)=(X+Y)(1+12%) 怎么解
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{X-Y=630 {X(1+20%)+Y(1-10%)=(X+Y)(1+12%) 怎么解
![{X-Y=630 {X(1+20%)+Y(1-10%)=(X+Y)(1+12%) 怎么解](/uploads/image/z/19770380-44-0.jpg?t=%7BX-Y%3D630+%7BX%281%2B20%25%29%2BY%281-10%25%29%3D%28X%2BY%29%281%2B12%25%29+%E6%80%8E%E4%B9%88%E8%A7%A3)
1.2x+0.9y=1.12x+1.12y
0.08x=0.22y
x=2.75y
代入x-y=630
2.75y-y=630
1.75y=630
y=360
y=2.75y=990
0.08x=0.22y
x=2.75y
代入x-y=630
2.75y-y=630
1.75y=630
y=360
y=2.75y=990
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