Adding and Subtracting Polynomials

Mathematics 7

Prepared by: Teacher Maria

Review Time!

- Monomial Ex. 2x, 5x, 2y, 6y
- Binomial Ex. 3x+5, 6x+3y
- Trinomial Ex. 3s-5t+7, 2x+9y-8
- Polynomial Ex. 3x+4y-5z+6w

Different types of Polynomials

Motivation

Instruction:
​The class will be divided into four (4) groups and will play a short quiz on Quizizz. The code for the quiz is sent on the group chat of the class. The group who will gain the highest score will receive a badge that is equivalent to 10 points.

Multiple Choice

Q1. The variables x and y are the same.

• True

• False

Multiple Choice

Q2. $$9-10$$ is equal to $$19$$ .

• True

• False

Multiple Choice

Q3. The sum of $$2x$$ and $$3x$$ is $$5x$$ .

• True

• False

Multiple Choice

Q4. The difference of $$3x$$ and $$4y$$ is $$3x-4y$$ .

• True

• False

What does it have to do with our lesson?

Addition and Subtraction of Polynomial

Objectives

At the end of the lesson, the learners will be able to:

• add and subtract polynomial expressions;

• demonstrate the steps for adding and subtracting of polynomials using the appropriate mathematical operations; and

• demonstrate the application of addition and subtraction of polynomials in real-life situations through an amazing race activity.

Defining terms

Like Terms

Unlike Terms

Defining terms

Like Terms

• Like Terms are terms whose variables, along with their exponents, are the same.

• For example, 2x, 7x, -2x, etc. are all like variables.

Defining terms

Like Terms

• Like Terms are terms whose variables, along with their exponents, are the same.

• For example, 2x, 7x, -2x, etc. are all like variables.

Unlike Terms

• Unlike Terms are terms whose either variables, exponents, or both variables and exponents are the not the same.

• For example, 2, 7x², -2y², etc. are all unlike variables.

Multiple Choice

Which of the following are like terms?

• x² and 2x

• 3x and 4y
• 5x and 5x²

• 14x and -5x

Multiple Choice

Which of the following are unlike terms?

• x³ and 3x

• 5y and 4y

• y and 10y

• 14x and -5x

How Can We Add Polynomials?

• To add polynomials, simply combine like terms or similar terms.

• To combine similar terms, get the sum of the numerical coefficients and copy the same literal coefficients.

How Can We Add Polynomials?

• To add polynomials, simply combine like terms or similar terms.

• To combine similar terms, get the sum of the numerical coefficients and copy the same literal coefficients.

Rules in adding polynomials

Rule 1: Always take like terms together while performing addition.

Rule 2: Signs of all the polynomials remain the same.

Example:

Example:

Example:

Fill in the Blanks

5𝑎 + (2𝑎 + 6)

Fill in the Blanks

(2𝑥 + 4) + (4𝑥 – 1)

How Can We Subtract Polynomials?

• To subtract a polynomial from another polynomial, change the sign of the subtrahend and proceed to addition.

How Can We Subtract Polynomials?

• To subtract a polynomial from another polynomial, change the sign of the subtrahend and proceed to addition.

subtrahend

minuend

Keep, Change, Change

sign of
minuend

sign of subtrahend

operation to +

How Can We Subtract Polynomials?

• To subtract a polynomial from another polynomial, change the sign of the subtrahend and proceed to addition.

Rules in subtracting polynomials

Rule 1: Always take like terms together while performing subtraction.

Rule 2: Apply the Keep, Change, Change technique.

Example:

Example:

Example:

Example:

Example:

Fill in the Blanks

(5𝑥 + 4) - (7𝑥 + 3)

Fill in the Blanks

(9𝑥 + 3) − (−4𝑥 + 5)

Summary of the lesson

Summary of the lesson

In adding polynomials:

• only add like terms

Summary of the lesson

In adding polynomials:

In subtracting polynomials:

• only add like terms

• only subtract like terms

• apply the Keep - Change - Change method

Do you have any questions and clarification?

Activity 1
Amazing race with a twist

Activity 1
Amazing Race with a Twist

​Direction: With the same groupings, each group has to go through the three (3) stations prepared and each station contains a question that will be answered in 1 minute through the Quizizz app. Each question corresponds to a certain point and the group with the highest score will gain 30 points.

Multiple Choice

Station 1 Question

• A. 5𝑥 − 5

• B. 5𝑥 + 5

• C. 5𝑥 – 11

• D. 5𝑥 + 11

Fill in the Blanks

Station 2 Question

Fill in the Blanks

Station 3 Question

Congratulations to the winning group

Activity 2
Quiz Bowl

Activity 2 - Quiz Bowl

Direction: With the same groupings, each group will be given 20 seconds to answer each question on Quizizz. There will be a total of 10 questions and the group with the highest points will gain 20 points.

Fill in the Blanks

Q1. Add the two given polynomials 3x + 2y and 4y + 5z.

Fill in the Blanks

Q4. Subtract 3a-3b+c from 4a+5b-3c.

Fill in the Blanks

Q10. When adding or subtracting polynomials we add/subtract the

.

What can you say about the activities we did?

What can you say about the activities we did?

You will be answering a 20-item quiz at home on Quizizz using you own accounts individually. The person who will get the 1st place will be given a special prize next meeting.

​Assignment Time!

Questions? Clarifications?

Good bye class!

​Prepared by: Teacher Maria