1. Do Now 10/13/11 In your notebook, simplify the expressions below.
-2a – 3 + 4a + 8
-4a – 3(a + 8)
solve multi-step equations using algebra

2. -3(x + 4) = -3(x) + (-3)(4) = -3x + (-12) -2a – 3 + 4a + 8 -2a + 4a
Remember this…
-3(x + 4)
= -3(x)
+ (-3)(4)
= -3x
+ (-12)
-2a – 3 + 4a + 8
-2a + 4a
+ (-3) + 8
= 2a
+ 5

3. -4a – 3(a + 8) -4a +(-3)(a + 8) -4a + (-3a) + (-24) -7a + (-24)
Remember this…
-4a – 3(a + 8)
-4a +(-3)(a + 8)
-4a
+ (-3a)
+ (-24)
-7a
+ (-24)

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

5. Section 3.2 “Solving a Multi-Step Equation”
How can you get the “unknown” by itself?
8x - 3x - 10 = 20
Solving Multi-Step Equations
STEP 1-
STEP 2- Combine like terms.
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.

6. Solving Multi-Step Equations…
Isolate the variable! Get ‘x’ by itself.
8x – 3x – 10 = 20
5x – 10 = 20
Combine like terms.
5x – =
Add 10 to each side.
5x = 30
Simplify. = 30 5 5x
Divide each side by 5.
x = 6
Simplify.

7. 8x – 3x – 10 = 20 x = 6 8(6) – 3(6) – 10 = 20 Check Your Work!
8(6) – 3(6) – 10 = 20
Are both sides equal?

8. Solving a Multi-Step Equation
Solving Multi-Step Equations
STEP 1 - Distributive Property
STEP 2- Combine like terms.
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.

9. Solving Multi-Step Equations Using the Distributive Property…
6x – 2(x – 5) = 46
Distributive property.
6x – 2x + 10 = 46
Combine like terms.
4x + 10 = 46
Subtract 10 from each side.
4x + 10 – 10 = 46 – 10
Simplify.
4x = 36
Divide each side by 4. = 4x 4 36
Simplify.
x = 9

10. x = 9 6(9) – 2(9 – 5) = 46 Check Your Work! Are both sides equal?
6x – 2(x – 5) = 46
x = 9
6(9) – 2(9 – 5) = 46
Are both sides equal?

11. Guided Practice 2) p – 17p – 6 = -38 1) 6x – 2x + 11 = -5

12. Guided Practice 6x – 2(x + 11) = -6 6x + (-2x) + (-22) = -6

13. Guided Practice 27 = 3c – 3(6 – 2c) 27 = 3c + (-18) + 6c