7.2 Properties of Rational 7.2 Properties of Rational ExponentsExponents

By: L. Keali’i AliceaBy: L. Keali’i Alicea

Review of Properties of Exponents Review of Properties of Exponents from section 6.1from section 6.1

aamm * a * ann = a = am+nm+n

(a(amm))nn = a = amnmn

(ab)(ab)mm = a = ammbbmm

aa-m-m = = = a= am-nm-n

==

n

m

aa

ma1

m

ba

m

m

ba

These all work These all work for fraction for fraction

exponents as exponents as well as integer well as integer

exponents.exponents.

Ex: Simplify. (no decimal answers)Ex: Simplify. (no decimal answers)

a.a. 661/21/2 * 6 * 61/31/3 = 6= 61/2 + 1/31/2 + 1/3 = 6= 63/6 + 2/63/6 + 2/6

= 6= 65/65/6

b. (27b. (271/31/3 * 6 * 61/41/4))22

= (27= (271/31/3))22 * (6 * (61/41/4))22

= (3)= (3)22 * 6 * 62/42/4

= 9 * 6= 9 * 61/21/2

c.c. (4(433 * 2 * 233))-1/3-1/3

= (4= (433))-1/3-1/3 * (2 * (233))-1/3-1/3

= 4= 4-1-1 * 2 * 2-1-1

= = ¼¼ * * ½½

= = 11//88

d.d.

= = == = =

3

41

41

9

18

43

43

9

18 43

918

43

2** All of these examples were in rational exponent form to begin with, so the answers should be in the same form!

Ex: Simplify.Ex: Simplify.

a.a. === = = = 55

b.b. == = = = = 2 2

Ex: Write the expression in Ex: Write the expression in simplest form.simplest form.

a.a. = == = ==

b.b. = =

= = = =

==

33 525 3 5253 125

3

3

432

3

432

3 8

4 64 4 416 44 416

4 4 2

4

87

4

4

87 Can’t have a tent in

the basement!

4

4

4

4

22

87

4

4

1614

2144

** If the problem is ** If the problem is in radical form to in radical form to begin with, the begin with, the answer should be in answer should be in radical form as well.radical form as well.

Ex: Perform the indicated operationEx: Perform the indicated operation

a.a. 5(45(43/43/4) – 3(4) – 3(43/43/4)) = 2(4= 2(43/43/4))

b. b. == == = =

c. c. == == = = 33 381

33 3327 33 333

3 32

33 5625 33 55125

33 555 3 5 6

If the original problem is in radical form,

the answer should be in radical form as well.

If the problem is in rational exponent form, the answer should be in rational exponent form.

More ExamplesMore Examples

a.a.

b.b.

c.c.

d. d.

2x x

6 6x x

11 11y y

4 8r 4 44 rr 4 44 4 rr

rr 2r

Ex: Simplify the Expression. Ex: Simplify the Expression. Assume all variables are positive.Assume all variables are positive.

a.a.

b.b. (16g(16g44hh22))1/2 1/2

= 16= 161/21/2gg4/24/2hh2/22/2

= 4g= 4g22hh

c. c.

3 927z 3 93 27 z 33z

510

5

yx

5 10

5 5

yx

2yx

d.34

1

32

6

18

tr

rs33

2411

3 tsr

332

43

3 tsr

Ex: Write the expression in simplest Ex: Write the expression in simplest form. Assume all variables are positive.form. Assume all variables are positive.

a. a. 4 149412 fed 4 144 94 44 12 fed 4 23424 12 ffeed

4 232 12effde

b. 57

2

hg

537

32

hhhg

No tents in the basement!

510

32

hhg

2

5 32

hhg

c.4

32

3

515

dffed )4(13

2133 fed 53

223 fed

** Remember, solutions must be in the same form as the ** Remember, solutions must be in the same form as the original problem (radical form or rational exponent form)!!original problem (radical form or rational exponent form)!!

Ex: Perform the indicated operation. Ex: Perform the indicated operation. Assume all variables are positive.Assume all variables are positive.

a.a. xx 38 x5

b. 41

41

63 ghgh 41

3gh

c. 44 5 662 xxx 44 662 xxxx 4 63 xx

d. sss 26 s126 s5

AssignmentAssignment7.2 A (2-34 even)7.2 A (2-34 even)15 minutes to work on this!!15 minutes to work on this!!