[tex] - 12 {e}^{ - x } + 8 = 7 \\ - 12 {e}^{x} = - 1 \\ {e}^{ - x} = \frac{ - 1}{ - 12} \\ {e}^{ - x} = \frac{1}{12} \\ [/tex]
taking e to the other side will equal ln , bringing -x down
[tex] - x = ln( \frac{1}{12}) \\ x = - ln( \frac{1}{12} )[/tex]
insert this in your calculator, you will get :
[tex]x = 2.484906... \\ [/tex]
rounding off to nearest thousand :
[tex]x = 2.485[/tex]
hope this helps...
