Download Algebra: Equations - Skyline R2 School

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Objective
Solve equations using mental math
Vocabulary
Equation
A sentence in math that contains an equal sign
Vocabulary
Solution
A number that makes the equation true
Vocabulary
Solving an equation
The process of finding a solution
Vocabulary
Defining the variable
To choose a variable to represent one of the
unknowns
Math Symbols
=
≠
is equal to
is not equal to
Example 1 Solve an Equation Mentally
Example 2 Graph the Solution of an Equation
Example 3 Write an Equation to Solve a Problem
Example 4 Find a Solution of an Equation
Solve
Just because it says “mentally” there is still
work to do
mentally
Write equation
6
THINK What number divided by 2
equals 3?
You know that 2  3 = 6, so try 6 as
your solution
Replace x with 6
1/4
Solve
6
mentally
Divide 6 by 2
Bring down = 3
3 = 3
This is a true statement so 3 is the
solution
Answer: The solution is 3
1/4
Solve
Answer:
mentally.
17
1/4
Graph the solution of the equation
Write equation
Remember: You solved this equation
in example 2 and the solution was 6
Draw a number line that includes the
solution
2/4
Graph the solution of the equation
Plot 6 on the number line
Answer:
2/4
Graph the solution of the equation
Answer:
2/4
ENTERTAINMENT An adult paid $18.50 for herself
and two students to see a movie. If the two student
tickets cost $11 together, what is the cost of the adult
ticket?
Variable
Let a represent the cost of an
adult movie ticket.
Words
The cost of one adult ticket plus
two student tickets is $18.50.
Two student tickets cost $11
Write
Equation
Total cost is $18.50
a + 11 = 18.50
3/4
ENTERTAINMENT An adult paid $18.50 for herself
and two students to see a movie. If the two student
tickets cost $11 together, what is the cost of the adult
ticket?
a + 11 = 18.50
7.50 + 11 = 18.50
Solve equation mentally
THINK What number added to 11 =
18.50
You know that 18.50 - 11 is 7.50,
so try 7.50 as your solution
Replace a with 7.50
3/4
ENTERTAINMENT An adult paid $18.50 for herself
and two students to see a movie. If the two student
tickets cost $11 together, what is the cost of the adult
ticket?
7.50 + 11 = 18.50
Add 7.50 + 11
18.50 = 18.50
Bring down = 18.50
This is a true statement so
7.50 is the solution
Answer: The cost of an adult movie ticket is $7.50.
3/4
ICE CREAM Julie spends $9.50 at the ice cream
parlor. She buys a hot fudge sundae for herself and
ice cream cones for each of the three friends who are
with her. Find the cost of Julie’s sundae if the three
ice cream cones together cost $6.30.
Answer:
$3.20
3/4
MULTIPLE- CHOICE TEST ITEM
What value of x is a solution of
A5
B6
C7
D8
12 - x = 5
Write equation
12 - 7 = 5
THINK What number subtracted from
12 equals 5
You know that 12 - 5 is 7, so try 7 as
your solution
Replace x with 7
4/4
MULTIPLE- CHOICE TEST ITEM
What value of x is a solution of
A5
B6
C7
D8
12 - 7 = 5
Subtract 7 from 12
Bring down = 5
5 = 5
This is a true statement so 7 is the
solution
Choose the correct multiple choice
letter
Answer: C
4/4
*
MULTIPLE- CHOICE TEST ITEM
What value of x is a solution of
A 34
B 35
C 36
D9
Answer: B
4/4
Assignment
Lesson 1:5
Algebra: Equations
14 - 35 All