How do you simplify ${(\dfrac{{125}}{{64}})^{ - \dfrac{2}{3}}}$ ?
Answer
611.4k+ views
Hint: To solve the given expression, first we should know that the given expression belongs to the property of exponents. So, we will solve this question by using the property of exponent of both division and multiplication.
Complete step-by-step solution:
The given expression belongs to the property of exponents i.e. ${(\dfrac{{125}}{{64}})^{ - \dfrac{2}{3}}}$ .
A property of exponents states that:
${(\dfrac{a}{b})^{ - m}} = {(\dfrac{b}{a})^m}$
Hence,
$
{(\dfrac{{125}}{{64}})^{ - \dfrac{2}{3}}} \\
= {(\dfrac{{64}}{{125}})^{\dfrac{2}{3}}} \\
= {(\dfrac{{64}}{{125}})^{(\dfrac{1}{3}).2}} \\
$
We also know that ${a^{m.n}} = {({a^m})^n}$
$ = {\{ {(\dfrac{{64}}{{125}})^{\dfrac{1}{3}}}\} ^2}$
Now, again we know that:
\[{a^{\dfrac{1}{m}}} = \sqrt[m]{a}\]
$
= {(\sqrt[3]{{\dfrac{{64}}{{125}}}})^2} \\
= {(\sqrt[3]{{\dfrac{{{4^3}}}{{{5^3}}}}})^2} \\
= {(\sqrt[3]{{{{(\dfrac{4}{5})}^3}}})^2} \\
= {(\dfrac{4}{5})^2} \\
= \dfrac{{{4^2}}}{{{5^2}}} \\
= \dfrac{{16}}{{25}} \\
$
Hence, the simplified form of the given expression is \[\dfrac{{16}}{{25}}\].
Note: As discussed earlier, there are majorly six laws or rules defined for exponents. Below, all the laws are represented:
(1.) ${a^m}\times {a^n} = {a^{m + n}}$
(2.) ${({a^m})^n} = {a^{m.n}}$
(3.) ${(a\times b)^n} = {a^n}.{b^n}$
(4.) ${(\dfrac{a}{b})^n} = \dfrac{{{a^n}}}{{{b^n}}}$
(5.) \[\dfrac{{{a^m}}}{{{a^n}}} = {a^{m - n}}\]
(6.) $\dfrac{{{a^m}}}{{{a^n}}} = \dfrac{1}{{{a^{m - n}}}}$
Complete step-by-step solution:
The given expression belongs to the property of exponents i.e. ${(\dfrac{{125}}{{64}})^{ - \dfrac{2}{3}}}$ .
A property of exponents states that:
${(\dfrac{a}{b})^{ - m}} = {(\dfrac{b}{a})^m}$
Hence,
$
{(\dfrac{{125}}{{64}})^{ - \dfrac{2}{3}}} \\
= {(\dfrac{{64}}{{125}})^{\dfrac{2}{3}}} \\
= {(\dfrac{{64}}{{125}})^{(\dfrac{1}{3}).2}} \\
$
We also know that ${a^{m.n}} = {({a^m})^n}$
$ = {\{ {(\dfrac{{64}}{{125}})^{\dfrac{1}{3}}}\} ^2}$
Now, again we know that:
\[{a^{\dfrac{1}{m}}} = \sqrt[m]{a}\]
$
= {(\sqrt[3]{{\dfrac{{64}}{{125}}}})^2} \\
= {(\sqrt[3]{{\dfrac{{{4^3}}}{{{5^3}}}}})^2} \\
= {(\sqrt[3]{{{{(\dfrac{4}{5})}^3}}})^2} \\
= {(\dfrac{4}{5})^2} \\
= \dfrac{{{4^2}}}{{{5^2}}} \\
= \dfrac{{16}}{{25}} \\
$
Hence, the simplified form of the given expression is \[\dfrac{{16}}{{25}}\].
Note: As discussed earlier, there are majorly six laws or rules defined for exponents. Below, all the laws are represented:
(1.) ${a^m}\times {a^n} = {a^{m + n}}$
(2.) ${({a^m})^n} = {a^{m.n}}$
(3.) ${(a\times b)^n} = {a^n}.{b^n}$
(4.) ${(\dfrac{a}{b})^n} = \dfrac{{{a^n}}}{{{b^n}}}$
(5.) \[\dfrac{{{a^m}}}{{{a^n}}} = {a^{m - n}}\]
(6.) $\dfrac{{{a^m}}}{{{a^n}}} = \dfrac{1}{{{a^{m - n}}}}$
Recently Updated Pages
Find the greatest six digit number that is exactly class 8 maths CBSE

What is the time difference between India and Cana class 8 social science CBSE

Compare LPG and wood as fuels class 8 chemistry CBSE

In Indian rupees 1 trillion is equal to how many c class 8 maths CBSE

30 opposite words in English from a to z class 8 english CBSE

How many cubic feet equals to 1 unit sand class 8 maths CBSE

Trending doubts
What is BLO What is the full form of BLO class 8 social science CBSE

Citizens of India can vote at the age of A 18 years class 8 social science CBSE

Full form of STD, ISD and PCO

One cusec is equal to how many liters class 8 maths CBSE

What are the methods of reducing friction. Explain

What is the difference between rai and mustard see class 8 biology CBSE


