x+y=830 =>x=830-y .....①
(1-6%)x+(1+5%)y=830+3 =>94x+105y=83300 ....②
将①代入②得94*(830-y)+105y=83300即11y=83300-830*94=5280
y=480 代入①得x=350
(1)x+y=830 二元一次方程,有无数组解,部分正整数解如下:
x y=830-x
1 829
2 828
3 827
4 826
5 825
6 824
7 823
8 822
9 821
10 820
11 819
12 818
13 817
14 816
15 815
16 814
17 813
18 812
19 811
20 810
......
(2)(1-6%)x+(1+5%)x=830+3
0.94x+1.05x=833
1.99x=833
x=83300/199
=418.59296482412060301507537688442......
“解得x=350,过程啊过程,”什么意思?