Solve this system using Gaussian elimination

[TonyC]

2 1 1 | 4
-1 2 1 | 3
7 6 5 | 19

Need a little help please

 

[morry]

Im not going to do the whole thing, but I like to try and eliminate the stuff below the top left number first.

Say, R3+7R2, will get rid of the -7. And will make the bottom row 0 20 12 | 40, id then divide by 2. Makes things easier. Then move onto another number.

I used to really suck at this, it takes a lot of goes before you can do it without trouble.

 

[morry]

Im not going to do the whole thing, but I like to try and eliminate the stuff below the top left number first.

Say, R3+7R2, will get rid of the -7. And will make the bottom row 0 20 12 | 40, id then divide by 2. Makes things easier. Then move onto another number.

I used to really suck at this, it takes a lot of goes before you can do it without trouble.

 

[TonyC]

Thank you, the book doesn't explain to good and I just needed a jump start.