解三元一次方程、要有过程的蛤、越详细越好.
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/16 11:53:39
解三元一次方程、要有过程的蛤、越详细越好.
{ X+Y+Z=3.3 X/3+Y/4+Z/5=51/60 X/5=Y/4+Z/3=53.4/60
{ X+Y+Z=3.3 X/3+Y/4+Z/5=51/60 X/5=Y/4+Z/3=53.4/60
![解三元一次方程、要有过程的蛤、越详细越好.](/uploads/image/z/16412083-43-3.jpg?t=%E8%A7%A3%E4%B8%89%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E3%80%81%E8%A6%81%E6%9C%89%E8%BF%87%E7%A8%8B%E7%9A%84%E8%9B%A4%E3%80%81%E8%B6%8A%E8%AF%A6%E7%BB%86%E8%B6%8A%E5%A5%BD.)
X+Y+Z=3.3
X/3+Y/4+Z/5=51/60
X/5+Y/4+Z/3=53.4/60
同分后:
X+Y+Z=3.3 ①
20X+15Y+12Z=51 ②
12X+15Y+20Z=53.4 ③
②-12*①得:8x+3y=11.4 ④
①*20-③得:8x+5y=12.6 ⑤
由④⑤解得:x=1.2,y=0.6
将x=1.2,y=0.6代入①解得:z=1.5
X/3+Y/4+Z/5=51/60
X/5+Y/4+Z/3=53.4/60
同分后:
X+Y+Z=3.3 ①
20X+15Y+12Z=51 ②
12X+15Y+20Z=53.4 ③
②-12*①得:8x+3y=11.4 ④
①*20-③得:8x+5y=12.6 ⑤
由④⑤解得:x=1.2,y=0.6
将x=1.2,y=0.6代入①解得:z=1.5