Math, asked by aryan3014, 9 months ago


 ( \frac{2}{3}) ^{ - x}   + ( \frac{2}{3})^{ - 4}   = ( \frac{2}{3})^{5}
Find "x"



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Answers

Answered by 217him217
1

=> (2/3)^-x + (2/3)^-4 = (2/3)^5

=> (2/3)^-x + (3/2)^4 = (2/3)^5

=> (2/3)^-x = (32/243) - (81/16)

=> (2/3)^-x = -4.931

which is not possible,because any positive number has any power it's answer will also positive, but in this case we see negative value (-4.931) which is not correct...

ao that X doesn't exist..

hey bro.. this is correct ans..

Answered by pandaXop
0

Step-by-step explanation:

Given:

  • ( \frac{2}{3}) ^{ - x}  + ( \frac{2}{3 } ) ^{ - 4}  = ( \frac{2}{3} ) ^{5}

Solution:

We have

( \frac{2}{3} ) ^{ - x}  + ( \frac{2}{3} ) ^{ - 4}  = ( \frac{2}{3} ) ^{ - 5}  \\  =  > ( \frac{3}{2} ) ^{x}  + ( \frac{3}{2} ) ^{4}  = ( \frac{3}{2} ) ^{5}  \\  \\  =  > ( \frac{3}{2} ) ^{x}  + ( \frac{3 \times 3 \times 3 \times 3}{2 \times 2 \times 2 \times 2} ) = ( \frac{3 \times 3 \times 3 \times 3 \times 3}{2 \times 2 \times 2 \times 2 \times 2} ) \\  \\  =  > ( \frac{3}{2}^{x} ) + ( \frac{81}{16} ) = ( \frac{243}{32} ) \\  \\  =  > ( \frac{3}{2}  ^{x} ) =  \frac{243}{32}  -  \frac{81}{16} \:  take \: lcm \\  \\  =  > ( \frac{3}{2})  ^{x}  =  \frac{243 - 162}{32}  \\  \\  =  > ( \frac{3}{2}  ^{x}) =  \frac{81}{32}  \\  \\  =  > ( \frac{3}{2}  ^{x} ) = ( \frac{3}{2} ) \: or \\  \\  =  > ( \frac{2}{3}  ^{ - x} ) = ( \frac{2}{3}  ^{ - 1} ) \: bases \: are \: same \: so \: power \: wil \: be \: also \: equal \\  \\  =  > ( - x) = ( - 1) \\  \\  =  > x = 1

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