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

Exercise #1

Insert the corresponding expression:

(7×11×193×12×15)4= \left(\frac{7\times11\times19}{3\times12\times15}\right)^{-4}=

Video Solution

Step-by-Step Solution

The given expression is:
(7×11×193×12×15)4 \left(\frac{7\times11\times19}{3\times12\times15}\right)^{-4}

To solve this expression, we need to apply the rules of exponents, specifically the rule for powers of a fraction. For any fraction(ab)n \left(\frac{a}{b}\right)^{-n} , the expression is equivalent to(ba)n \left(\frac{b}{a}\right)^n .
Therefore, negative exponents indicate that the fraction should be flipped and raised to the positive of that exponent.

Substitute the terms into this formula:
1. Flip the fraction: (3×12×157×11×19) \left(\frac{3\times12\times15}{7\times11\times19}\right)
2. Raise both numerator and denominator to the power of 4:
Thus, we have:
(3×12×157×11×19)4 \left(\frac{3\times12\times15}{7\times11\times19}\right)^{4}

Now evaluating each term individually:
- In the numerator:
- 34×124×154 3^4\times12^4\times15^4
- In the denominator:
- 74×114×194 7^4\times11^4\times19^4

Applying the negative exponent rule, each individual factor in both numerator and denominator should be inverted, altering the exponents to negative:
1. Numerator becomes: 34×124×154 3^{-4}\times12^{-4}\times15^{-4}
2. Denominator becomes: 74×114×194 7^{-4}\times11^{-4}\times19^{-4}

Rewriting the expression, we achieve:
74×114×19434×124×154 \frac{7^{-4}\times11^{-4}\times19^{-4}}{3^{-4}\times12^{-4}\times15^{-4}}

This matches precisely the provided solution.

The solution to the question is:74×114×19434×124×154 \frac{7^{-4}\times11^{-4}\times19^{-4}}{3^{-4}\times12^{-4}\times15^{-4}}

Answer

74×114×19434×124×154 \frac{7^{-4}\times11^{-4}\times19^{-4}}{3^{-4}\times12^{-4}\times15^{-4}}

Exercise #2

(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 #3

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #4

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #5

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #6

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #7

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #8

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #9

Insert the corresponding expression:

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

Video Solution

Answer

207 20^7

Exercise #10

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #11

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #12

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #13

Insert the corresponding expression:

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

Video Solution

Answer

604 60^4

Exercise #14

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #15

Insert the corresponding expression:

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

Video Solution

Answer

34 3^4

Exercise #16

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #17

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #18

Insert the corresponding expression:

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

Video Solution

Answer

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

Exercise #19

Insert the corresponding expression:

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

Video Solution

Answer

A+B are correct

Exercise #20

Insert the corresponding expression:

(1×54×6)2= \left(\frac{1\times5}{4\times6}\right)^{-2}=

Video Solution

Answer

a' + b' are correct