anonymous 3 years ago X=-In2/(3In2+In5) round the answer 2 digits after the decimal sign.

1. Mertsj

What is another form of 3ln2?

2. anonymous

In(8)?

3. Mertsj

Yes. And what is another form of ln8 + ln5 ?

4. anonymous

idk In(40)?

5. Mertsj

Yes. So now we have:

6. Mertsj

$x=- \frac{\ln 2}{\ln 40}$

7. Mertsj

So pick up your calculator and find the ln of 2, divide it by the ln of 40, round the answer to two decimal places and change it to its opposite.

8. Mertsj

What did you get?

9. anonymous

I got -0.1879018247

10. anonymous

but im not sure if its right 2^3x+1=5^-x= (3x+1)In2=-xIn5 3xIn2+In2=-xIn5 3xIn2+xIn5=-In2 X(3In2+In5)=-In2 X=-In2/(3In2+In5) =-In2/In40 = -0.1879018247

11. Mertsj

Round it to -.19

12. anonymous

did i do that right? x= -.19 ?

13. Mertsj

Replace x with -.19 and see if it makes the original equation true.

14. Mertsj

Also, that is what I got.