三元一次方程组x+y+z=130,0000.035x+0.058y+0.085z=7950x=y-15000求x,y,z不是整数用分数表达XYZ,都写出来

Question

三元一次方程组
x+y+z=130,000
0.035x+0.058y+0.085z=7950
x=y-15000
求x,y,z 不是整数用分数表达
XYZ,都写出来

Answer 1

0.035x+0.058y+0.085z=7950
35x+58y+85z=7950000 ①
x+y+z=130000
85x+85y+85z=130000*85=11050000 ②
② - ①,得50x+27y=3100000 ③
把x=y-15000代入 ③,得
50*（y-15000）+27y=3100000
即77y=3100000+50*15000=3850000
y=50000
∴x=y-15000
=50000-15000
=35000
z=130000-35000-50000=45000
∴x=35000,y=50000,z=45000