初一二元一次方程组
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\uff081\uff09 x+y=7200 1.1x+0.8y=7200\u89e3\u5f97 x=4800 ,y=2400
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[2000x+1000\uff083.24%\u2014x\uff09] X\uff081\u201420%\uff09\uff1d43.92
[2000x+32.4\u20141000x] X 0.8 \uff1d43.92
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1000x+32.4 \uff1d54.9
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[1000x+64.8\u20142000x\uff09] X 0.8\uff1d43.92
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1000x \uff1d64.8\u201454.9
1000x \uff1d9.9
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x+2y=3…………②
①+②，得：
4x=12
x=3
代入②，得：
3+2y=3
2y=0
y=0
解为：
x=3
y=0
①连等号都没有，怎么做啊，你用追问的形式补全我就可以写详细，你光补充题目，不用追问的话，我不会知道你什么时候补了
看到你追问别人的了
两式相加，得到4x=12所以x=3带回②得到2y=0所以y=0
3X-2Y=9①
X+2Y=3②
解：
①+②可得
4x=12
x=3
将x=3代入②
3+2y=3
y=0
所以方程组的解为
{x=3
{y=0
你好，请问3X-2Y等于几啊？
将1,2相加，得4x=12，所以x=3,再将3代入1,2任意一个中即得y=0
你想 求助什么？
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