1. TODAY IN GEOMETRY…  Review: Solving Linear Systems by Graphing  STATs for Ch.10 Test  Learning Goal: Solving Linear Systems by Substitution and Elimination.  In Class Practice

2. WARM UP: Solve each system by graphing.

3. HOW DID YOU “SHAPE” UP?? Results for ALL of my Geometry classes: GRADE NUMBER OF STUDENTS WHO TOOK THE CH.10 TEST (28 pts.) 1 ST PERIOD2 ND PERIOD4 TH PERIOD6 TH PERIODTOTAL A647724 B593623 C146718 D22015 F1144322 Avg.18.9221.8321.8522.7521.34

4. 3.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTION STEPS FOR SOLVING A LINEAR SYSTEM BY SUBSTITUTION: STEP 1: Solve for 1 variable for one of the two equations (it doesn’t matter which equation you start with and which variable you choose to solve for). STEP 2: Substitute one equation into the other and solve for the given variable. STEP 3: Substitute the solution from STEP 2 into the equation you solved for from STEP 1 and solve for the given variable. THIS IS MUCH EASIER WITH AN EXAMPLE!

5. 3.2 SOLVING LINEAR SYSTEMS BY SUBSTITUTION

9. SOLVING LINEAR SYSTEMS BY SUBSTITUTION WORKSHEET: Work on problems 1-6 20 Minutes

10. 7.3 SOLVING LINEAR SYSTEMS BY ELIMINATION STEPS FOR SOLVING A LINEAR SYSTEM BY ELIMINATION WITH ELIMINATION FIRST: STEP 1: Align the variables with x and y on the same side of each equation. Choose a variable to eliminate and multiply each equation by the coefficients. Then ADD or SUBTRACT the equations. STEP 2: SOLVE the equation for the remaining variable. STEP 3: Substitute the solution from STEP 2 into either equation to solve for given variable. THIS IS MUCH EASIER WITH AN EXAMPLE!

11. 3.2 ELIMINATION WITH MULTIPLICATION FIRST I’ll eliminate the x’s first Now I have matching coefficients! Solve this system using elimination.

12. 3.2 SOLVING LINEAR SYSTEMS BY ELIMINATION EXAMPLE 1 Continued: Same signs: SUBTRACT

13. 3.2 ELIMINATION WITH MULTIPLICATION FIRST I’ll eliminate the x’s first Now I have matching coefficients! Solve this system using elimination.

14. 3.2 SOLVING LINEAR SYSTEMS BY ELIMINATION EXAMPLE 2 Continued: Same signs: SUBTRACT

15. 3.2 ELIMINATION WITH MULTIPLICATION FIRST I’ll eliminate the y’s first Sometimes you only need to multiply one equation! Now I have matching coefficients! Solve this system using elimination.

16. 3.2 SOLVING LINEAR SYSTEMS BY ELIMINATION EXAMPLE 3 Continued: Same signs: SUBTRACT

17. 3.2 ELIMINATION WITH MULTIPLICATION FIRST I’ll eliminate the x’s first Now I have matching coefficients! Solve this system using elimination.

18. 3.2 SOLVING LINEAR SYSTEMS BY ELIMINATION PRACTICE Continued: Same signs: SUBTRACT

19. IN CLASS WORK #1: Substitution and Elimination WS TURN IN ASSIGNMENT TODAY.