1. Do Now 10/30/09 Copy HW in your planner. Copy HW in your planner. –Text p. 134, #12-28 evens & #34 & #36 Did you turn in POTW#8?

2. Objective SWBAT solve equations with variables on both sides SWBAT solve equations with variables on both sides

3. Equation- mathematical sentence with an equal sign mathematical sentence with an equal sign Like a scale, both sides must be EQUAL in order to be balanced.

4. Section 3.3 “Solving Equations with Variables on Both Sides” How can you get the “unknown” by itself? How can you get the “unknown” by itself? Solving Equations with Variables on Both Sides STEP 1- Use distributive property and combine like terms. STEP 2- Collect variables on one side of the equation. STEP 3- “Undo” addition and/or subtraction. STEP 4- “Undo” multiplication and/or division. STEP 5- Solve for the variable. STEP 6- Check your work. 7 - 8x = 4x – 17

5. 7 – 8x = 4x – 17 + 8x 12 7 = 12x – 17 7 = 12x – 17 To get all the ‘x’ variables on one side “add 8x.” To get the “12x” by itself “add 17” to both sides. +17 +17 24 = 12x 24 = 12x To get the ‘x’ by itself “divide by 12” to both sides. itself “divide by 12” to both sides. + 8x 12 2 = x 2 = x

6. Check Your Work! x = 2 7 – 8(2) = 4(2) – 17 Are both sides equal? 7 – 8x = 4x – 17

7. 1) 6x + 11 = 2x – 5 1) 6x + 11 = 2x – 5 2) -17p – 6 = -38 – p 2) -17p – 6 = -38 – p 4x + 11 = -5 4x = -16 x = -4 -16p – 6 = -38 -16p – 6 = -38 -16p = -32 -16p = -32 p = 2 p = 2 Practice

8. Isolate the variable! Get ‘x’ by itself. Solving Equations with Variables on Both Sides… 9x – 5 = 4x + 15 5x – 5 = 15 5x = 20 x = 4 Write original equation. Distributive property Subtract 4x from each side. Add 5 to each side. Divide each side by 5. 9x – 5 = 2(2x + 7.5)

9. Check Your Work! = 4 x = 4 Are both sides equal? 9x – 5 = 2 (2x + 7.5) 9(4) – 5 = 2 (2(4) + 7.5)

10. Isolate the variable! Get ‘x’ by itself. Solving Equations with Variables on Both Sides…If Possible 2 – 15n +15n = -15n +15n + 10 2 – 15n +15n = -15n +15n + 10 2 = 10 No Solution 2 – 15n = 5(-3n +2) 2 – 15n = -15n + 10 2x + 10 = 2x + 10 2x + 10 = 2x + 10 All Numbers 3x +10 – x = 2(x +5) 2x + 10 = 2(x+5)

11. 4 + 2x + 8 = 2(x + 6) 4 + 2x + 8 = 2(x + 6) 7p + 6 – 3p = -38 + 4p 2x + 12 = 2(x + 6) 2x + 12 = 2x + 12 All numbers 4p + 6 = -38 + 4p 4p + 6 = -38 + 4p 6 ≠ -38 6 ≠ -38 No solution No solution Guided Practice

12. Homework Text p. 134, #12-28 evens & #34 & #36