Question

(16^x ) (256)= 4^6,then find 40(9^x+ 9^-x)/9^x- 9^-x

Answer 1

Answer:

Correct option is

A

ln2−ln3

ln(

3

−1)+ln2

6

x

+4

x

=9

x

divide by 4

x

to form (

2

3

)

x

4

x

6

x

+1=

4

x

9

x

(

2

3

)

x

+1=(

2

3

)

2x

((

2

3

)

x

)

2

−(

2

3

)

x

−1=0

So (

2

3

)

x

=

2

1±

1−4.1(−1)

=

2

1±,

5

For positive solution

(

2

3

)

x

=

2

1+

5

Applying logarithm

xln(

2

3

)=ln(

2

1+

5

)

ln

b

a

=lna−lnb

x=

ln3−ln2

ln(1+

5

)−ln2

.

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