Examples with solutions for Powers of a Fraction: Calculating powers with negative exponents

Exercise #1

(23)4=? (\frac{2}{3})^{-4}=\text{?}

Video Solution

Step-by-Step Solution

We use the formula:

(ab)n=(ba)n (\frac{a}{b})^{-n}=(\frac{b}{a})^n

Therefore, we obtain:

(32)4 (\frac{3}{2})^4

We use the formula:

(ba)n=bnan (\frac{b}{a})^n=\frac{b^n}{a^n}

Therefore, we obtain:

3424=3×3×3×32×2×2×2=8116 \frac{3^4}{2^4}=\frac{3\times3\times3\times3}{2\times2\times2\times2}=\frac{81}{16}

Answer

8116 \frac{81}{16}

Exercise #2

7483(17)4=? 7^4\cdot8^3\cdot(\frac{1}{7})^4=\text{?}

Video Solution

Step-by-Step Solution

We use the formula:

(ab)n=anbn (\frac{a}{b})^n=\frac{a^n}{b^n}

We decompose the fraction inside of the parentheses:

(17)4=1474 (\frac{1}{7})^4=\frac{1^4}{7^4}

We obtain:

74×83×1474 7^4\times8^3\times\frac{1^4}{7^4}

We simplify the powers: 74 7^4

We obtain:

83×14 8^3\times1^4

Remember that the number 1 in any power is equal to 1, thus we obtain:

83×1=83 8^3\times1=8^3

Answer

83 8^3

Exercise #3

(132)0(213)2(132)5=? (\frac{13}{2})^0\cdot(\frac{2}{13})^{-2}\cdot(\frac{13}{2})^{-5}=\text{?}

Video Solution

Answer

(213)3 (\frac{2}{13})^3

Exercise #4

Insert the corresponding expression:

(49)5= \left(\frac{4}{9}\right)^{-5}=

Video Solution

Answer

4595 \frac{4^{-5}}{9^{-5}}

Exercise #5

Insert the corresponding expression:

(1013)4= \left(\frac{10}{13}\right)^{-4}=

Video Solution

Answer

104134 \frac{10^{-4}}{13^{-4}}

Exercise #6

Insert the corresponding expression:

(23)11= \left(\frac{2}{3}\right)^{-11}=

Video Solution

Answer

211311 \frac{2^{-11}}{3^{-11}}

Exercise #7

Insert the corresponding expression:

(14)2= \left(\frac{1}{4}\right)^{-2}=

Video Solution

Answer

1242 \frac{1^{-2}}{4^{-2}}

Exercise #8

Insert the corresponding expression:

(25)3= \left(\frac{2}{5}\right)^{-3}=

Video Solution

Answer

2353 \frac{2^{-3}}{5^{-3}}

Exercise #9

Insert the corresponding expression:

(37)4= \left(\frac{3}{7}\right)^{-4}=

Video Solution

Answer

3474 \frac{3^{-4}}{7^{-4}}

Exercise #10

Insert the corresponding expression:

(120)7= \left(\frac{1}{20}\right)^{-7}=

Video Solution

Answer

207 20^7

Exercise #11

Insert the corresponding expression:

(57)7= \left(\frac{5}{7}\right)^{-7}=

Video Solution

Answer

(75)7 \left(\frac{7}{5}\right)^7

Exercise #12

Insert the corresponding expression:

(1013)2= \left(\frac{10}{13}\right)^{-2}=

Video Solution

Answer

(1310)2 \left(\frac{13}{10}\right)^2

Exercise #13

Insert the corresponding expression:

(1521)3= \left(\frac{15}{21}\right)^{-3}=

Video Solution

Answer

(2115)3 \left(\frac{21}{15}\right)^3

Exercise #14

Insert the corresponding expression:

(160)4= \left(\frac{1}{60}\right)^{-4}=

Video Solution

Answer

604 60^4

Exercise #15

Insert the corresponding expression:

(25)2= \left(\frac{2}{5}\right)^{-2}=

Video Solution

Answer

(52)2 \left(\frac{5}{2}\right)^2

Exercise #16

Insert the corresponding expression:

(13)4= \left(\frac{1}{3}\right)^{-4}=

Video Solution

Answer

34 3^4

Exercise #17

Insert the corresponding expression:

(38)5= \left(\frac{3}{8}\right)^{-5}=

Video Solution

Answer

(83)5 \left(\frac{8}{3}\right)^5

Exercise #18

Insert the corresponding expression:

(56)3= \left(\frac{5}{6}\right)^{-3}=

Video Solution

Answer

(65)3 \left(\frac{6}{5}\right)^3

Exercise #19

Insert the corresponding expression:

(1017)5= \left(\frac{10}{17}\right)^{-5}=

Video Solution

Answer

(1710)5 \left(\frac{17}{10}\right)^5

Exercise #20

Insert the corresponding expression:

(817×13)6= \left(\frac{8}{17\times13}\right)^{-6}=

Video Solution

Answer

A+B are correct