Transcript Writing Linear Equations

Writing and Solving
Linear Equations
Madison Houser
Expression vs. Equation
O A linear expression is a combination of
terms where the highest power of the
variable is 1
O 3x+4
O 5x+9
O An equation is a statement in which the
value of 2 expressions are equal
O 3x+4 = 5x+6
Words that Mean “Equal”
O Is
O Are
O Was
O Were
O Will be
O Gives
O Yields
O Spent
O Total of
O Sold for
There are other words that aren’t on here
Step 1: Define the Problem
O Read the problem carefully
- Read a few times before you start Defining
O Bennett and his friends decide to go bowling. The cost for
the group is $15 for shoe rentals plus $4 per game. If they
spent $47, how many games did they pay for?
O Identify what you are trying to find
O How many games did the group pay for?
O Determine what information is available to help you find
it.
O $15 for shoes for the entire group
O $4 per game
O They spent $47
Step 2: Assign Variables
O Choose a variable to assign to an unknown
quantity in the problem.
O Use g to represent the cost per game
O If other unknown quantities exist, express
them in terms of the selected variables.
O No other unknowns
Step 3: Translate into an
Equation
O Use the relationships among the known and
unknown quantities to form an equation.
O Bennett and his friends decide to go bowling. The
cost for the group is $15 for shoe rentals plus $4 per
game. If they spent $47, how many games did they
pay for?
O The relationships will be referred to in terms of
operations:
O
O
O
O
Addition
Subtraction
Multiplication
Division
O 4g + 15 = 47
You try!
O The Ace Telephone Co. charges a flat monthly
fee of $22.00 for a telephone line and $0.20
per minute for long distance calls. If you want to
spend $27 for one month how many long
distance minutes can you use per month?
O Equation: 0.20m + 22 = 27
Step 4: Solve the Equation
O Determine the value of the variable
O 4g + 15 = 47
O Use the result to find any other unknown
quantities in the problem.
Step 5: Check the
Reasonableness of Your Answer
O Check to see if your answer makes sense
within the context of the problem.
O If not, check your work for errors and try
again.
Step 6: Answer the Question
O Write a clear statement that answers the
question(s) posed.
O Bennett and his friends paid for 9 games of
bowling.
You Try! Continued..
O The Ace Telephone Co. charges a flat monthly
fee of $22.00 for a telephone line and $0.20 per
minute for long distance calls. If you want to
spend $27 for one month how many long
distance minutes can you use per month?
O Equation: 0.20m + 22 = 27
O Solution: You can use 25 long distance minutes
per month.
Other Equations to Solve
3x + 15 = x + 25
2x + 3 = 6 – (2x – 3)
1
2 1
x + = (x + 4)
2
3 3