The document contains notes from a math lesson. It includes assignments that are due, such as a test and worksheet. The warm-up questions cover percentages, sales tax, fractions, and perimeter. The lesson explains that variables can represent unknown numbers in expressions and equations. Examples show evaluating expressions when values are substituted for variables, and solving simple equations by inspection.

1. lesson 14.notebook September 09, 2013
Assignment:
1­­>Set 14 (evens) ­ Due Tomorrow (9/10)
2­­>Test Signed??

2. lesson 14.notebook September 09, 2013
Lesson 14 Warm­Up:
1) Express 125% as a decimal.
2) Estimate 8.25% sales tax on a $39.99 purchase.
3) Convert to a percent.
4) If 4 is the divisor, and 8 is the quotient, what is the dividend?
5) If each side of a square is 2 in., then what is the perimeter of the
square?
4
9
1
2

3. lesson 14.notebook September 09, 2013
Lesson 14:
*FYI...
Sometimes we use a letter to represent an unidentified
number.
expression­­> 5x
**To evaluate an expression...substitute numbers in place of the
variable(s) and calculate the result!
constant
or
coefficient
variable

4. lesson 14.notebook September 09, 2013
Examples ­ Lesson 14
A) A formula for the perimeter of a rectangle is P = 2l + 2w.
Find P when l is 15 cm and w is 12 cm.
B) In the expression 4ac, what is the constant?

5. lesson 14.notebook September 09, 2013
C) Evaluate 4ac, when a = 1 and c = 12.
Solve each equation by inspection. Check your answer.
D) w + 5 = 16 check:
E) m ­ 6 = 18 check:

6. lesson 14.notebook September 09, 2013
F) 25 ­ n = 11 check:
G) 5x = 30 check:
H) d = 8 check:
4

7. lesson 14.notebook September 09, 2013
I) 12 = 6 check:
z
J) 2a ­ 1 = 9 check:
K) 20 = 3f ­ 1 check:
L) 2r + 3 = 15 check: