Lesson 1.7
Reading and Writing Equations
Focus: Translate statements into equations.
A/ Algebraic Expressions - Review
What algebraic expression can you write for the statement... 'nine less
than a number?'
What is the meaning of the expression 6n + 2?
How can you evaluate the expression 5n + 3 for n = 4?
Algebraic expression review:
Terminology
Equation:
Ex)
Expression:
Ex)
Explore p. 35
PART 1:
Write an algebraic expression
for these statements:
Think of a number.
Multiply it by 3.
Add 4.
The answer is 13.
What is the original number?
Use a variable to
represent your
number
Use the following steps to write your equation:
1) Which variable did you use for the number?
2) What expression did you write to represent "Multiply it by 3"
3) What expression did you write to represent "Multiply it by 3. Add 4."?
4) How did you use the answer to find the original number?
Equation: ___________________
Part 2:
Write your own riddle.
Trade riddles with a partner.
Write an algebraic expression for your partner's statements.
Find your partner's original number.
Which variable did you use for your number?
How did you create your own number riddle?
Connect p. 35
Zena bought 3 CDs. Each CD costs the same amount.
The total cost was $36. What was the cost of 1 CD?
Step 1: Write an equation to represent this situation.
Step 2: Solve the equation
Examples (More practice!)
Write an equation for each sentence...
1. Three more than a number is 15.
2. Five less than a number is 7.
3. A number subtracted from 5 is 1.
4. A number divided by 3 is 10.
5. Eight added to 3 times a number is 26.
Assignment: Pages 36-37 # 1 - 8
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