Systems of Inequalities

Today in math class we learned about systems if inequalities. Well, more like a review now since we were on Thanksgiving Break and all. Mr. S gave us 7 steps for substitution. 1) pick variable. 2) Solve for variable. 3) Substitute. 4) CLT. 5) Solve. 6) Sub. into original equation 7) Solve. Technically he put 4 steps but I wanted to be very specific and put three extra steps. Now, the moment you've been waiting for...an example!


EX: 2x + 4y = 10
      x + y = 7  isolate your x! --> x = 7 - y
      2(7 - y) + 4y = 10
      14 - 2y + 4y = 10
      14 + 2y = 10
      2y = -4
      y = -2


Then to find your "x" you would put in substitute the "y" into the original equation.


EX: x = (-2) - 7
      x = 9


Then your coordinates are (9,-2). Simple, easy, and quick to do! Just don't mess up on your negatives...the process must be PERFECT!!!