How do you solve $ln(x+8)-ln7=3$ ?

Question

4379 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-08-05T03:00:06

$x=7e^3-8 ~= 132.6$

$ln(x+8)-ln7=3$

Since $lna-lnb=ln(a/b)$

$ln(x+8)-ln7 = ln((x+8)/7)$

Since $lna=b -> a=e^b$
Our equation can be written as: $(x+8)/7=e^3$

Hence: $x+8 = 7e^3$

$x=7e^3-8 ~=132.6$

How do you solve ln(x+8)-ln7=3ln(x+8)-ln7=3?