Lesson 6 subtraction of polynomials

Subtraction of Polynomials

Alexander M. Morron JrBNHS - Gawaran

To add polynomials, add the numerical coefficient of like term and copy the literal coefficient.

)8124( 2 xx )1296( 2 xx+Align like terms8124 2 xx

1296 2 xx

10x2 – 3x – 4

+

Recall:

To add polynomials, add the numerical coefficient of like term and copy the literal coefficient.

)3912( 2 xx )8127( 2 xx+Align like terms3912 2 xx8127 2 xx

19x2 + 3x – 5

+

Recall:

Subtract the following integers.

2.) 13 – (-4) =

1.) -11 – 3 =

Recall:

3.) -13 – (-5) =

4.) 10 – (-13) =

Note: a – b = a + (-b)

To subtract polynomials, change the sign of all terms of the subtrahend, change the operation to addition and proceed to addition of polynomials.

–

Align like terms

3x – 17

+

(11x – 7) (8x + 10 )

11x – 7

(8x + 10)–

– 8x – 10

To subtract polynomials, change the sign of all terms of the subtrahend, change the operation to addition and proceed to addition of polynomials.

–

Align like terms

x2 – 9x

+

(3x2 – 4x + 5) (2x2 + 5x – 10)

3x2 – 4x + 5

2x2 + 5x – 10–

– 2x2 – 5x + 10

+ 15

To subtract polynomials, change the sign of all terms of the subtrahend, change the operation to addition and proceed to addition of polynomials.

–

Align like terms

x3 + x2

+

(5x3 – 10x2 + 3x – 5) (4x3 – 11x2 + 3x + 5)

5x3 – 10x2 + 3x – 5

4x3 – 11x2 + 3x + 5–– 4x3 + 11x2 – 3x – 5

– 10

To subtract polynomials, change the sign of all terms of the subtrahend, change the operation to addition and proceed to addition of polynomials.

Align like terms

– 4x+ 8

+

Subtract 3x + 5 to 7x – 3

3x + 5

7x – 3 –– 7x + 3

To subtract polynomials, change the sign of all terms of the subtrahend, change the operation to addition and proceed to addition of polynomials.

Align like terms

4x – 8

+

Subtract 3x + 5 from 7x – 3

7x – 3

3x + 5 –– 3x – 5

Exercises

1. 21 y – (-7y)

2. -20x3 – (-3x3)

3. (9x2 + 16x + 12) – (14x2 + 2x – 7)

4. (10x2 + x + 16) – (3x – 4x2 + 10)

5. (3x2 – 2x – 6) – (3x2 – 2x + 6)

Application

Dan keeps 5p2 + 2p – 7 pesos in the bank. If his money earned p2 – p + 8 pesos as interest, what would be his latest bank balance?

Application

What must be subtracted to -24x to obtain 32x? 

If you subtract 8xy to 15xy will you get the same result when you subtract 8xy from 15xy?

Worksheet No. 6

Directions: Solve the following.

1. 14x2 − 15x2

2. (4x2 + 6x − 7) − (7x2 − 5x + 8)

3. (2x − 7x3 + 5) − (7 + 4x + 5x3) 

4. (3x3 + 4x2 + 5x − 7) − (2x3 − 7x2 + 5x − 7)

5.Verbal Writing:

Is the result of x2 + 5x − 7 subtracted from 3x2 − 7x − 8 the same with 3x2 − 7x − 8 subtracted to x2 + 5x − 7?