Question

Solve for x: 7^(x+1) - 7^(x-1) = 336sqrt7

Please show working out....

Also, don't put any random 'i don't know' 'I can't understand' 'ashdfaksdfhsadkf' 'mark me brainliest' answers. They aren't helpful at all... :(

Thanks guys!!!!

Answer 1

Required Answer:-

Given:

• $\rm {7}^{x + 1} - {7}^{x - 1} = 336 \sqrt{7}$

To find:

• The value of x.

Answer:

• The value of x is 2.5

Solution:

We have,

$\rm \implies {7}^{x + 1} - {7}^{x - 1} = 336 \sqrt{7}$

This can be written as,

$\rm \implies {7}^{x} \times 7 - {7}^{x} \times {7}^{ - 1} = 336 \sqrt{7}$

Taking 7ˣ as common, we get,

$\rm \implies {7}^{x} \times \bigg (7 - \dfrac{1}{7} \bigg) = 336 \sqrt{7}$

$\rm \implies {7}^{x} \times \bigg (\dfrac{49 - 1}{7} \bigg) = 336 \sqrt{7}$

$\rm \implies {7}^{x} \times \bigg (\dfrac{48}{7} \bigg) = 336 \sqrt{7}$

$\rm \implies {7}^{x} = \bigg (\dfrac{7}{48} \bigg) \times 336 \sqrt{7}$

$\rm \implies {7}^{x} = 7\times 7 \sqrt{7}$

$\rm \implies {7}^{x} = {7}^{2} \times {7}^{0.5}$

$\rm \implies {7}^{x} = {7}^{2 + 0.5}$

$\rm \implies {7}^{x} = {7}^{2.5}$

Comparing Base, we get,

$\rm \implies x = 2.5$

Hence, the value of x is 2.5

Answer 2

Answer:

$value \: of \: x \: is \: 2.5$