Question

Solve the following exponential equations.
10^(x+1) − 10^(x−1) = 1287

Answer 1

Answer:x=2.114

Explanation:

Given

`10^(x+1)-10^(x-1)=1287`

`10* 10^x-(10^x)/(10)=1287`

Let
`10^x=y`

`10y-(y)/(10)=1287`

`(100y-y)/(10)=1287`

`99y=1287* 10`

`y=(12870)/(99)=130`

`10^x=130`

Taking
`\log`both sides

`x\log (10)=\log (130)`

`x=(\log (130))/(1)`

`x=2.114`