Matlab 求解【九元一次方程组】急啊啊啊啊啊!1:0.04a+23.57b+c+3d+23e+23f+45.87g+400h+764i=1043.23752:0.04a+3.79b+c+d+8e+8f+10.56g+200h+176i=245.96253:0.03a+10.1b+c+d+10e+10f+32.4g+400h+540i=550.96254:0.04a+9.98b+c+2d+11e+11f+15.42g+257i

Matlab 求解【九元一次方程组】急啊啊啊啊啊!1:0.04a+23.57b+c+3d+23e+23f+45.87g+400h+764i=1043.23752:0.04a+3.79b+c+d+8e+8f+10.56g+200h+176i=245.96253:0.03a+10.1b+c+d+10e+10f+32.4g+400h+540i=550.96254:0.04a+9.98b+c+2d+11e+11f+15.42g+257i
Matlab 求解【九元一次方程组】急啊啊啊啊啊!
1:0.04a+23.57b+c+3d+23e+23f+45.87g+400h+764i=1043.2375
2:0.04a+3.79b+c+d+8e+8f+10.56g+200h+176i=245.9625
3:0.03a+10.1b+c+d+10e+10f+32.4g+400h+540i=550.9625
4:0.04a+9.98b+c+2d+11e+11f+15.42g+257i=420.525
5:0.04a+6.8b+c+d+8e+8f=222.5625
6:0.04a+5.48b+c+8e+8f+12.7g+200h+212i=292.5
7:0.04a+17.52b+c+3d+21e+21f+20.8g+200h+348i=722.0875
8:0.04a+11.99b+c+2d+20e+20f+34.5g+600h+576i=717.625
9:0.04a+12.5b+c+d+12e+12f+27.78g+600h+463i=601.3625
10:0.04a+9.75b+c+10e+10f+18.48g+400h+320i=450.8
11:24.97b+2d+19e+19f+11.74g+184i=769.575
12:4.68b+ci=98.6
如上方程组,abcdefghi分别为九个未知数,知道matlab软件会解这种方程组,但下载无法安装,尝试几个小时依旧无果,QAQ在这里向大手请教,请您务必认真计算啊,实验要用这方程组的解,谢谢您了!

Matlab 求解【九元一次方程组】急啊啊啊啊啊!1:0.04a+23.57b+c+3d+23e+23f+45.87g+400h+764i=1043.23752:0.04a+3.79b+c+d+8e+8f+10.56g+200h+176i=245.96253:0.03a+10.1b+c+d+10e+10f+32.4g+400h+540i=550.96254:0.04a+9.98b+c+2d+11e+11f+15.42g+257i
12个方程,9个未知数,方程组没有唯一解,求最小二乘解得：
A=[0.04 23.57 1 3 23 23 45.87 400 764;
0.04 3.79 1 1 8 8 10.56 200 176;
0.03 10.1 1 1 10 10 32.4 400 540;
0.04 9.98 1 2 11 11 15.42 0 257;
0.04 6.8 1 1 8 8 0 0 0;
0.04 5.48 1 0 8 8 12.7 200 212;
0.04 17.52 1 3 21 21 20.8 200 348;
0.04 11.99 1 2 20 20 34.5 600 576;
0.04 12.5 1 1 12 12 27.78 600 463;
0.04 9.75 1 0 10 10 18.48 400 320;
0 24.97 0 2 19 19 11.74 0 184;
0 4.68 1 0 0 0 0 0 1];
b=[1043.2375;245.9625;550.9625;420.525;222.5625;292.5;722.0875;717.625;601.3625;450.8;769.575;98.6];
%x=[a b c d e f g h i]'
x=A\b
Warning: Rank deficient, rank = 8, tol = 3.5954e-012.
x =
2.5187
19.9986
4.9082
1.5701
9.9983
0
4.9886
0.0660
0.1007
也可以用其中9个方程,解得：
A=[0.04 23.57 1 3 23 23 45.87 400 764;
0.04 3.79 1 1 8 8 10.56 200 176;
0.03 10.1 1 1 10 10 32.4 400 540;
0.04 9.98 1 2 11 11 15.42 0 257;
0.04 6.8 1 1 8 8 0 0 0;
0.04 5.48 1 0 8 8 12.7 200 212;
0.04 17.52 1 3 21 21 20.8 200 348;
0.04 11.99 1 2 20 20 34.5 600 576;
0.04 12.5 1 1 12 12 27.78 600 463];
b=[1043.2375;245.9625;550.9625;420.525;222.5625;292.5;722.0875;717.625;601.3625];
x=A\b
Warning: Matrix is close to singular or badly scaled.
Results may be inaccurate. RCOND = 2.502755e-021.
x =
1.0e+003 *
0.0000
0.0200
0.0050
0.0016
-7.0620
7.0720
0.0050
0.0001
0.0001
这个解近似奇异,也不一定准确