3. IN YOUR OWN WORDSHow can you write and evaluate an expression that represents a real-life problem? Give one example with addition, one with subtraction, one with multiplication, and one with division.

A
25.
k
+
10
=
25
+
10
=
35
Add 25 and 10.
b. Evaluate 4
⋅
n
when
n
=
12.
4
⋅
n
=
4
⋅
12
=
48
Multiply 4 and 12.
1.
Evaluate 24
+
c
when
c
=
9.
2.
Evaluate
d
−
17 when
d
=
30.
EXAMPLE
Evaluating Algebraic Expressions
1
Substitute 25 for
k
.
Substitute 12 for
n
.
Evaluate
a
÷
b
when
a
=
27 and
b
=
3.
a
÷
b
=
27
÷
3
=
9
Divide 27 by 3.
Evaluate the expression when
p
=
24 and
q
=
8.
3.
p
÷
q
4.
q
+
p
5.
p
−
q
6.
pq
EXAMPLE
Evaluating an Expression with Two Variables
2
Substitute 27 for
a
.
Substitute 3 for
b
.
Exercises 8 –19
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