1. Think about…
How is an equation like a balance scale?
In x + 1 = 3, what is the value of x? How do you know?

2. Variables on Both Sides
of an Equation
Mrs. Spanier
Algebra 1

3. Solve:
7x + 19 = -2x + 55
Combine like terms
Add 2x to both sides

4. Solve:
9x + 19 = 55
Subtract 19 on both sides

5. Solve:
9x = 36
Divide by 9 on both sides
x = 4

6. Check Your Work...
...Are Both Sides Equal?

7. Remember…
Same Sides Simplify
Opposite
Sides
Do the
Opposite

8. Solve: 2x + 3(4x – 3) = 8 – 3x 14x – 9 = 8 – 3x Distribute first
Combine like terms
14x – 9 = 8 – 3x

9. Solve:
14x – 9 = 8 – 3x
Solve as before…
17x – 9 = 8
17x = 17
x = 1

10. You try …
Now try the remaining 2 examples on your G.O. with a partner.

11. Solve:
16 – 3x = 11 + x
16 = x
5 = 4x
1.25 = x

12. Solve: -4 – 2 + 3x = 6x – 3 + 5 -6 + 3x = 6x + 2 -6 = 3x + 2 -8 = 3x

13. You Try:
7 + 3h = -1 – 5h
h = -1
5t – 4 = 4t – 4
t = 0

14. You Try:
-5r – 1 = 2(r + 24)
r = -7

15. You Try:
0.7w + 16 = – 4w
w = 2.4

16. The End