Originally Posted by
Adrian Solve the following system, where a, b, and c are constants:
x1 + x2 + x3 = a
2x1 + 2x3 = b
3x2 + 3x3 = c
If I put this into a matrix I get:
1 1 1 | a
2 0 2 | b
0 3 3 | c
I'm really not sure where to go from here because it seems to me like row 2 and 3 will cancel out making b and c equal 0, but I'm not really experienced with this and I'm not even sure what I'm trying to obtain in the end.
Thanks
subtract twice row 1 from row 2:
Code:
1 1 1 | a
0 -2 0 | b-2a
0 3 3 | c
Now add 3/2 times row 2 to row 3:
Code:
1 1 1 | a
0 -2 0 | b-a
0 0 3 | c + (3/2)(b-2a)
Now solve by back substitution.
RonL