Question

用数学软件帮我解一下这个线性方程组，谢谢。在线等

7A+18.2B+43.03C=48.79
18.2A+45.03B+190.472C=144.661
43.03A+190.472B+677.8756C=488.9851
syms x1 x2 x3
f1=7*x1+18.2*x2+43.03*x3=48.79;
f2=18.2*x1+45.03*x2+190.472*x3=144.661;
f3=43.03*x1+190.472*x2+677.8756*x3=488.9851;
[x1,x2,x3]=solve(f1,f2,f3)
直接在matlab里面运行就行了

Answer 1

>> syms x1 x2 x3
f1='7*x1+18.2*x2+43.03*x3=48.79';
f2='18.2*x1+45.03*x2+190.472*x3=144.661';
f3='43.03*x1+190.472*x2+677.8756*x3=488.9851';
[x1,x2,x3]=solve(f1,f2,f3)

x1 =

2.651814995704870955594634762305

x2 =

1.0526500813748260520128146341261

x3 =

0.25724061234125189784346572909063

>>

追问

对不起，刚才数据有误第一个系数是8，不是7.我知道答案和算法，我用LU分解法答案不对

追答

我重新计算了 发不上来 ...........

追问

是不是1.7、0.9、0.3？