11-6 rational expressions w/ like denominators

11-611-6 Rational Rational Expressions w/ Like Expressions w/ Like

DenominatorsDenominatorsEQEQ How are adding & How are adding & subtracting rational subtracting rational

expressions like adding & expressions like adding & subtracting fractions?subtracting fractions?

Rules If denominators are the same, just

add/subtract numerators. (keep denominators the same)

Simplify answer, if possible.

Examples1)

€

4b

15+16b

15

€

4b+16b

15

€

20b

15

€

4b

3

Dooyo

€

4x

5dy+7

5dy

€

4x + 7

5dy

Examples1)

€

4b

15+16b

15

€

4b+16b

15

€

20b

15

€

4b

3

2)

€

6c

c + 2+12

c + 2

€

6c +12

c + 2

€

6(c + 2)

c + 2

€

6

Dooyo

€

15x

33x + 9+

3

33x + 9

€

15x + 3

33x + 9

€

3(5x +1)

3(11x + 3)

€

5x +1

11x + 3

Examples3)

€

7x + 9

x − 3−x −5

x − 3

€

7x + 9 − x −5( )x − 3

€

7x + 9 − x + 5

x − 3

€

6x +14

x − 3

The minus must get distributed!

Dooyo

€

2y − 3

y + 5−3y + 7

y + 5

€

2y − 3− 3y − 7

y + 5

€

−y −10y + 5

Examples3)

€

7x + 9

x − 3−x −5

x − 3

€

7x + 9 − x −5( )x − 3

€

7x + 9 − x + 5

x − 3

€

6x +14

x − 3

4)

€

3s

11− s+−5s

s−11

€

−3ss−11

+−5s

s−11

€

−8ss−11

Summarize Explain to your neighbor the distributive

property is used when subtracting rational expressions.