1. 11 – 28 Journal
Evaluate the expression when x = 5
1) 3x
2) 4+x
3) 2x + 1

2. Where we were…
 Variables and expressions
 Variables – a letter that represents a number
 Example: x + 5; x is the variable
 Evaluating Expressions
 Evaluate when x = 2
 Example: x + 4
 Example: x + x

3. Where we are…
 Students will learn to…
 Solve basic equations using transformations.
 We will start off with the basics and move to more
difficult ones as we go.

4. Getting to Zero…
 How would you get the following numbers back to
zero??? (Hint: Use the number to help)
1) 4
2) 7
3) - 3
4) -5
5) -20

5. Getting to Zero…
 How would you get the following numbers back to
zero???
1) 4: Subtract four (- 4) (Think 4 minus 4)
2) 7: Subtract seven (- 7) (7 minus 7)
3) - 3: Add 3 (+3) (-3 plus 3)
4) -5: Add 5 (+5) (-5 plus 5)
5) -20: Add 20 (+20) (-20 plus 20)

6. Solving equations…
 Transformations – Operations you must do to BOTH
sides of an equation… (on each side of the equal sign)
Think of this as a positive 5. How
can I get a positive 5 back to zero?
 x + 5 = 10
 x + 5 = 10 Since you subtracted 5 from one side you must
subtract 5 from the other to keep it balanced.. (Think
teeter-totter.)
 x +5 - 5 = 10 -5
 x=5
+5 - 5 = 0, leaving just x
10 – 5 = 5, so…
x=5

7. Remember… SHOW ALL YOUR
STEPS!!!!
 x – 10 = 20 (How can I get negative 10 to zero?)
 x – 10 + 10 = 20 + 10
 So what is 20 + 10?
 x = 30
 I like to cross out the parts that equal zero

8. Number off from 1 -10
 The number you are is the number you need to answer.
1) x + 6 = 10
2) x – 5 = 15
3) x + 8 = 19
4) x – 4 = 30
5) n + 4 = 17
6) n – 10 = 25
7) n + 7 = 19
8) n – 12 = 21
9) n + 11 = 20
10) x – 3 = 15

9. Randomly choose 5 numbers
 Those 5 people will come to the board, show their
work and explain their thinking….

10. Ticket out the Door
1) A ____________ is a letter that represents a number.
2) If I add 5 to one side of the equal sign, what should I
do to the other side? ______________
3) Solve: x + 12 = 22