How do you evaluate ln (2x+3)=7?

1 Answer
Mar 10, 2018

x~~546.817 or x=(e^7 -3)/2

Explanation:

Remember, anytime you see ln, it is always equal to
loge (the e is a subscript). You work with them the same way as you would any other log.
Problem:
ln(2x+3)=7
Step 1: take loge of both sides.
ln(2x+3)=ln(e^7)
Step 2: Since the logs have the same bases, make the (2x+3)=(e^7) equal to each other
Step 3: Solve so the x is on the left side by itself:
x=(e^7 -3)/2
Step 4: if you need the decimal form, just plug in 2.718281828 (Euler's number) for e and solve.
x=(2.718281828 ^7 -3)/2 => x~~546.817