Math, asked by 2006shreyac5678, 2 months ago

evaluate (64)⁷/⁶×(27)²/³×2-⁷÷(√81)³/².​

Answers

Answered by Subhajitz
2

Answer:

\frac{1}{3}

Step-by-step explanation:

  = {(64)}^{7/6}  \times  {(27)}^{2/3} \times  {2}^{ - 7}   \div  {( \sqrt{81} )}^{3/2}  \\  =  {( {2}^{6} )}^{7/6}  \times  {( {3}^{3} )}^{2/3} \times  {2}^{ - 7}   \div  {( 9 )}^{3/2} \\  = {2}^{7}  \times  {3}^{2} \times  {2}^{ - 7}   \div  { ({3}^{2} )}^{3/2} \\   = {3}^{2}  \div  {3}^{3}  \\  =  {3}^{2 - 3}  \\  =  {3}^{ - 1}  \\   = \frac{1}{3}

I hope it helps. Mark me as brainliest.

Answered by TwilightShine
9

Answer :-

  • The answer is 1/3.

What to do?

  • Evaluate (64)⁷/⁶ × (27)²/³ × 2-⁷ ÷ (√81)³/².

Laws of exponents to be used :-

 \boxed{\rm \bigstar \:  {(a^{m} )}^{n}  =  {a}^{mn}}

  \boxed{\rm\bigstar \:  {a}^{m}  \times  {a}^{n}  =  {a}^{m + n}}

  \boxed{\rm \bigstar \:  {a}^{0}  = 1}

 \boxed{\rm \bigstar \:  {a}^{m}  \div  {a}^{n}  =  {a}^{m - n}}

 \boxed{\bigstar \:  \rm {a}^{ - m}  =  \dfrac{1}{a^{m}}}

Step-by-step explanation :-

  • Here, we have to evaluate the expression which is given to us. As it contains powers, we will use some laws of exponents and powers to evaluate it!

 \\

 \longmapsto \sf(64)^{ \frac{7}{6} }  \times (27)^{ \frac{2}{3} }  \times 2^{ - 7}  \div ( \sqrt{81} )^{ \frac{3}{2} }

Expressing 64 as a power with base 2,

  \longmapsto\sf({2}^{6} )^{ \frac{7}{6} }  \times  (27)^{ \frac{2}{3} }  \times 2^{ - 7}  \div  (\sqrt{81} )^{ \frac{3}{2} }

Expressing 27 as a power with base 3,

 \longmapsto\sf ({2}^{6} )^{ \frac{7}{6} }  \times ( {3}^{3} )^{ \frac{2}{3} }  \times  {2}^{ - 7}  \div  (\sqrt{81} )^{ \frac{3}{2} }

Finding the square root of 81,

 \longmapsto\sf ({2}^{6} )^{ \frac{7}{6} }  \times ( {3}^{3} )^{ \frac{2}{3} }  \times  {2}^{ - 7}  \div  (9)^{ \frac{3}{2} }

Expressing 9 as a power with base 3,

 \longmapsto\sf ({2}^{6} )^{ \frac{7}{6} }  \times ( {3}^{3} )^{ \frac{2}{3} }  \times  {2}^{ - 7}  \div  ( {3}^{2} )^{ \frac{3}{2} }

As (a^m)^n = a^mn, therefore,

 \longmapsto\sf{2}^{ \not6\times\frac{7}{ \not6}} \times  {3}^{ \not3 \times  \frac{2}{ \not3} }  \times  {2}^{ - 7}  \div  {3}^{ \not2 \times  \frac{3}{ \not2} }

Cancelling the numbers,

  \longmapsto\sf{2}^{7}  \times  {3}^{2}  \times  {2}^{ - 7}  \div  {3}^{3}

As a^m × a^n = a^m + n, therefore,

 \longmapsto \sf{2}^{7 + ( -  7)}  \times  {3}^{2}  \div  {3}^{3}

 \longmapsto\sf {2}^{0}  \times  {3}^{2}  \div  {3}^{3}

As a^m ÷ a^n = a^m - n, therefore,

\longmapsto \sf  \sf{2}^{0}  \times  {3}^{2 - 3}

  \longmapsto\sf{2}^{0}  \times  {3}^{ - 1}

As a^0 = 1, therefore,

\longmapsto \sf1 \times  {3}^{ - 1}

As a^-m = 1/a^m, therefore,

 \longmapsto\sf1 \times  \dfrac{1}{ {3}^{1} }

 \longmapsto\sf1 \times  \dfrac{1}{3}

 \longmapsto \sf\dfrac{1}{3}

 \\

Hence :-

  • Our answer is 1/3.

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