Question

If you were to use the elimination method to solve the following system, choose the new system of equations that would result after the variable z is eliminated in the first and second equations, then the second and third equations.

x – 3y – 3z = –13
x + 2y – z = –1
2x + 3y + 2z = 0
Answer
x – 3y = –13
2x + 3y = 0

x – 3y = –13
–2x – 9y = –10

2x + 3y = 0
4x + 7y = –2

–2x – 9y = –10
4x + 7y = –2

Answer 1

Hmmm, this is interesting. If I were doing this, I wouldn't get any of those. I would add the first and third equations to eliminate y. I'd take the result of that and use it to elminate z with the second equation, and get 4x = -14 and x = -7/2...so that's interesting.