1. Do Now
Simplify.
1. 5(7) – (18 – 11)
 (40 – 35)
(12 – 4) 34 49
161
111 83

2. 1.1 worksheet answers
1) 69 17) 18 3) 21 19) 18 5) 21 21) 19 7) 33 23) 0 9) 28 25) $10 11) 57 13) 39 15) 46

3. Learn to evaluate algebraic expressions.

4. A variable is a letter that represents an unknown number.
A constant is a number ; it cannot change.
An algebraic expression consists of one or more variables. It usually contains constants and operations.
Evaluate means to solve

5. Example A:
Evaluate k + 9 for each value of k.
k = 5
k = 2
k + 9
k + 9
5 + 9
Substitute 5 for k.
2 + 9
Substitute 2 for k. 14
Add. 11
Add.

6. Multiplication and division of variables can be written in several ways, as shown in the table.
When evaluating expressions, use the order of operations.

7. Example B:
Evaluate the expression for the given value of the variable.
4x – 3 for x = 2
4(2) – 3
Substitute 2 for x.
Multiply.
8 – 3 5
Subtract.

8. Example C:
Evaluate the expression for the given value of the variable.
s ÷ 5 + s, for s = 15
15 ÷
Substitute 15 for s.
3 + 15
Divide. 18
Add.

9. Example D:
Evaluate the expression for the given value of the variable.
5x2 + 3x, for x = 2
5(2)2 + 3(2)
Substitute 2 for x.
5(4) + 3(2)
Evaluate the power.
20 + 6
Multiply. 26
Add.

10. Check your understanding
Evaluate the expression for the given value of the variable.
1.) r ÷ 3 + r, for r = 12
12 ÷
Substitute 12 for r.
4 + 12
Divide. 16
Add.
2.) 4y2 + 2y, for y = 3
4(3)2 + 2(3)
Substitute 3 for y.
4(9) + 2(3)
Evaluate the power.
36 + 6
Multiply. 42
Add.

11. Check your understanding:6 a
3.)
+ 4b, for a = 3 and b = 2. 6 a
+ 4b 6 3
Substitute 3 for a and 2 for b.
+ 4(2)
Divide and multiply from
left to right.
2 + 8 10
Add.

12. Lesson Quiz Evaluate n + 7 for each value of n. 1. n = 25 2. n =31
Evaluate each algebraic expression for the given value of the variables
3. 6y – 5 for y = 7
4. 4x2 + 3x for x = 6
y for x = 4 and y = 3
6. The expression 7d gives the number of days in d weeks. Evaluate 7d for d = 12. How many days are in 12 weeks? 32 38 37
162 56 x 23 84

13. 7. Evaluate m + 4 for m = 19.
A. 21
B. 27
C. 23
D. 28

14. 8. Evaluate 7x – 8 for x = 5.
A. 20
B. 27
C. 22
D. 32

15. 9. Evaluate 6x2 + 5x for x = 5.
A. 185
B. 85
C. 175
D. 50

16. 39 x
10. Evaluate y for x = 3 and y = 5.
A. 38
B. 44
C. 54
D. 64

17. 11. The expression 12n gives the number of months in n years
11. The expression 12n gives the number of months in n years. Evaluate 12n for n = 3. How many months are in 3 years?
A. 12 months
B. 24 months
C. 36 months
D. 48 months