1. OBJ: Solve Linear systems graphically & algebraically Do Now: Solve GRAPHICALLY 1) y = 2x – 4 y = x - 1 Do Now: Solve ALGEBRAICALLY *Substitution OR Linear Combination 2) 2x + 3y = 5 2x + y = 4 IN YOUR NOTEBOOK….

2. 3.6 Solving Systems of Linear Equations in Three Variables CHOOSE THE SAME VARIABLE TO ELIMINATE FROM EACH SET: EQN 1&2 THEN EQN 2&3 SOLVE AGAIN BUT USING THE NEW EQNS THIS TIME SUBSTITUTE TO FIND THE LAST VARIABLE

3. 3x + 2y + 4z = 11 2x – y + 3z = 4 5x – 3y + 5z = -1 * FIND WHICH VARIABLE YOU CAN ELIMINATE FROM EQN 1 & 2 AND EQN 2 & 3 Ex:

4. * LETS PICK TO ELIMINATE “y” 3x + 2y + 4z = 11 2x – y + 3z = 4

5. * SINCE YOU ELIMINATED “y” YOU NEED TO ELIMINATE THE SAME VARIABLE AGAIN NOW 2x – y + 3z = 4 5x – 3y + 5z = -1

6. * SOLVE THE NEW EQUATIONS FROM EQN 1&2: 7x + 10z = 19 FROM EQN 2&3: -x – 4z = -13

7. * SUBSTITUTE BACK INTO ANY OF THE ORIGINAL EQUATIONS TO FIND THE REMAINING VARIABLE 3x + 2y + 4z = 11

8. * WRITE THE SOLUTION AS AN ORDERED TRIPLE (-3, 2, 4)