Question

Solve the system by elimination?
{-2x + 2y + 3z = 0
{-2x - y + z = -3
{2x + 3y + 3z = 5
Someone help me please? I need to finish this quiz, I'm falling behind in my classes. :/

Answer 1

I'll call the the equations 1, 2 and 3.
Add 1 to 3 to get
\[5y + 6z = 5\]Add 2 to 3 to get
\[2y+4z = 2\]You can now solve these simultaneous equations to get y and z.
Substituting the solutions to that problem into any of the equations in the question gets you your x.