1. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Learning Goals:
I can add subtract polynomials

2. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials

3. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Determine: (x2 – 3x + 5) – (-3x2 + 2x – 1)
We are starting with: x2 – 3x + 5

4. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
From this we need to take away: -3x2 + 2x – 1
The problem is we don’t have any of these tiles to take away

5. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
From this we need to take away: -3x2 + 2x – 1

6. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Now, what do we have left?

7. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
So, when we subtracted (-3x2 + 2x – 1) from (x2 – 3x + 5) we really added
+3x2, -2x, and +1.

8. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
When subtracting polynomials, ADD the OPPOSITE.
Step One: Change the subtraction ( - ) sign inbetween the polynomials to addition (+)
Step Two: Change all the signs inside the second polynomial
Step Three: Add the polynomials

9. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Example: (-3x2 + 4x – 1) – (2x2 + 3x – 5)

10. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Example: (4x2 + 4x + 8) – (-9x2 + 6x + 1)

11. Lesson 4: Subtracting Polynomials
MFM1P
Lesson 4: Subtracting Polynomials
Homework/Practice
Pg. 265 #5, 7, 8, 10, 11