EVALUATING
EXPRESSIONS
1-3
VOCABULARY…
1. Coefficient – numerical factor (a
number that comes in front of a
variable)
2. Evaluate – replacing each
variable with a number in order
to solve using the order of
operations
EXAMPLES…
~Evaluate~
1.) 4y – 15, for y = 9
4(9) – 15
36 – 15
21
EXAMPLES…
2.) 63 – 5(x), for
x=7
63 – 5(7)
3.) 4(t + 3) + 1, for
t=8
4(8 + 3) + 1
63 – 35
4(11) + 1
28
44 + 1
45
EXAMPLES…
4.) 3ab + c ÷ 2 , for a = 2, b = 5, c = 10
3ab + c ÷ 2  3(2)(5) + 10 ÷ 2
6(5) + 10 ÷ 2
30 + 10 ÷ 2
30 + 5
35
EVALUATING
EXPRESSIONS…
• The value of a variable expression
depends upon the value of the
variable.
• By substituting different digits for the
variables, you will ultimately get
different answers for the variable
expressions.
Putting the numbers and
expressions into a chart form
will help you see these different
values…
x
3x + 2
Answers…
0
3(0) + 2
2
1
3(1) + 2
5
2
3(2) + 2
8
3
3(3) + 2
4
3(4) + 2
11
14
x
0
1
2
3
4
17 + x
17 + 0
17 + 1
17 + 2
17 + 3
17 + 4
Answers…
X
4x – 2x
Answers…
0
1
2
4(0) – 2(0)
0
4(1) – 2(1)
4(2) – 2(2)
2
3
4(3) – 2(3)
4
6
4
4(4) – 2(4)
8
17
18
19
20
21
EXAMPLE…
• Complete the table for the given value of
the variables.
k
10
11
12
13
14
5+k
15
16
17
18
19
2k – 9
11
13
15
17
19