Question

Solve for x
67=0.4e^5x

Answer 1

okay, this one is easy

Answer 2

ok where do I begin

Answer 3

Firstly, divide both sides by 0.4 so that we can cancel it out

Answer 4

ok \[\frac{ 67 }{ 0.4}\]=e^5x

Answer 5

Do you know what you get if you take the natural logarithm of e?

Answer 6

no

Answer 7

Try it in your calculator

Answer 8

I got 1

Answer 9

\[\ln(\frac{67}{0.4})=5x*\ln(e)\]

Answer 10

perfect, so we know that ln(e)=1, do you see how to solve the rest of the problem?

Answer 11

I think so hold on a minute and let me do it

Answer 12

so is the answer 1.024

Answer 13

It's easy to check, just plug it right back into the equation

Answer 14

yup ok thanks

Answer 15

Did you have any more logarithm questions? also, any question involving something like 0.4e, if you can divide out the coefficient, you will always know that ln(e)=1, which makes the rest a lot easier for you.

Answer 16

I do it is Solve for x again [4e ^{x}+e ^{x}(4x-3)=0\]

Answer 17

I'm not sure how that's formatted