Equations

Gateway to the Future
Math 1
Junior High School

Chapter 3 EQUATIONS

​MYP Math

​Keita:​" useful ''

Chapter 3

Equations​

Section 1: Equations

​How many did we collect?

The student council at Keita's school​ held a fundraising effort to collect 50-yen coins for people affected by the war in Ukraine. Keita wanted to find out how many coins were in the box without opening it, so he decided to weigh it. (see page 74)

Section 1: Equations

​How many did we collect?

The student council at Keita's school​ held a fundraising effort to collect 50-yen coins for people affected by the war in Ukraine. Keita wanted to find out how many coins were in the box without opening it, so he decided to weigh it. (see page 74)

​Think--Pair--Share

• Collaborating: Work with a partner, ​think about how you will help Keita find our how many coins were collected. Decide on the best method. Use numbers and other math symbols in your work.

• Reasoning: Why do you think Keita decided not to open the box to find out the amount collected for the fund raising?​

Video Response

Think-Pair-Share

Open Video Recorder

Section 1: Equations

​How many did we collect?

The student council at Keita's school​ held a fundraising effort to collect 50-yen coins for people affected by the war in Ukraine. Keita wanted to find out how many coins were in the box without opening it, so he decided to weigh it. (see page 74)

Section 1: Equations

​How many did we collect?

The student council at Keita's school​ held a fundraising effort to collect 50-yen coins for people affected by the war in Ukraine. Keita wanted to find out how many coins were in the box without opening it, so he decided to weigh it. (see page 74)

Section 1: Equations

​How many did we collect?

The student council at Keita's school​ held a fundraising effort to collect 50-yen coins for people affected by the war in Ukraine. Keita wanted to find out how many coins were in the box without opening it, so he decided to weigh it. (see page 74)

Equations

​Equations and their solutions

​Equations and their solutions

​Concept Check

Open Ended

Q2: State (with proof) which of the following equations have 3 as the solution

Math & ME​

​Recall an experience when Math has made an impact in your life. Think of a word or phrase that can be used to describe it. Be ready to share by posting your ideas in the word cloud.

​Reflection

Word Cloud

Math and me

Properties of equalities

​There are several ways to solve an equation.

​When solving equations, we use property of equalities as a general rule.

​Properties of equalities

​1 An equality holds true if the same number is added to both sides

​If A = B, then A + C = B + C

​If x - 5 = -1​,

then x - 5 + 5 = -1 + 5

x = 4​

​

​2 An equality holds true if the same number is subtracted from both sides

If A = B, then A - C = B - C

​If x + 13 = 8​,

then x + 13 - 13 = 8 - 13

x = -5​

​

​

​Concept Check

Open Ended

Use the properties of equalities to solve:

x - 9 = 3

Open Ended

Use the properties of equalities to solve:

x - 8 = -10

Open Ended

Use the properties of equalities to solve:

x - $$\frac{1}{2}$$  = $$\frac{1}{2}$$  

​This method show the step by step process of solving equations using the properties of equality.

​This method show the shortcut way of solving equations using the properties of equality.

​left side

​right side

​(opposite operation)

​(other side of the equal sign)

Open Ended

Use the properties of equalities to solve:

x + 7  =  15

Open Ended

Use the properties of equalities to solve:

x + 6  =  2

Open Ended

Use the properties of equalities to solve:

x + 1.2  =  0

​Properties of equalities

​Concept Check

Open Ended

Use the properties of equalities to solve:

$$\frac{x}{7}=3$$  

Open Ended

Use the properties of equalities to solve:

$$\frac{x}{4}=-5$$  

Open Ended

Use the properties of equalities to solve:

$$-\frac{1}{6}x=2$$  

Open Ended

Use the properties of equalities to solve:

$$5x=45$$  

Open Ended

Use the properties of equalities to solve:

$$-8x=48$$  

Open Ended

Use the properties of equalities to solve:

$$12x=3$$  

Practice Problems
p79