Question

Answer 1

`7^[x+3]+7^x=2^3 .2107`

`7^x .7^3+7^x=16856`

`7^x .(7^3+1)=16856`

`7^x .344=16856`

`7^x=16856:344=49`

`7^x=7^2`

`x=2`

Answer 2

\(7^{x+3}+7^x=2^3.2107\)

\(7^x\left(7^3+1\right)=2^3.2107\)

\(7^x.344=2^3.2107\)

\(7^x=49=7^2\)

\(x=2\)

Answer 3

`7^(x+3) +7^x = 2^3 .2107`

`=> 7^x ( 7^3 + 1) = 8.2107`

`=> 7^x . 344 = 16856`

`=>7^x = 49`

`=> 7^x = 7^2`

`=>x=2`