How do you solve #log_10(x+7) - log_10(x-7)=1#?

1 Answer
Nov 12, 2015

Part solution given. It has been taken to a point that is much easier to solve.

Explanation:

You are dealing with logs in that the #color(blue)("all")# of the left is logs. Consequently the value on the right is a value obtained from taking a log

Let b be a constant
Write the right hand side as :
#-> log_10(b)=1#

#10^1 = b" so " b=10#

Subtraction of logs is the consequence of division of the source values. So now we have:

#(x+7)/(x-7)=10#

#=> x+7 = 10x -70#

I will let you take over from this point and complete the calculations.