Question

Eliminate the "z" variable in the last two equations by finding opposite coefficients and adding. What is the resulting equation?

x + 3y + 2z = –16
2x – y + 2z = –15
2x – 2y – z = 1

Answer 1

Did you try? multiply the last equation by 2 (that means 2 times everything on the left side, and 2 x 1 on the right side). Add the equation to the 2nd equation.

Answer 2

Multiply the last equation by 2 so the "z's" will cancel out leaving you with this.