Natural Logs

𝑒9−5𝑥=6981I got the decimal approximation of the answer but I have to enter the log version into webwork as well and because it is so specific about how the answer must be formatted I cannot seem... more

let 𝑈(𝑥, 𝑦) be defined for all x > 0, y > 0 by𝑈(𝑥, 𝑦) = ln(𝑥^a+y^a)-Ln(y^a) where 𝛼 is a positive constant find U'1(x,y), U'2(x,y) and U''12(x,y)

Please show work

(ee )x = 15 

Create a formula then find the temp of the pie after 120 minuites 

I don't get how to do this and I'm not sure how to use the ln    y' = 

A sample of 400 g of radioactive lead-210 decays to polonium-210 according to the function A(t)=400e-0.032t,where t is time in years. Find the amount of radioactive lead remaining after (a) 4... more

I am really confused how to solve this, and how to put it into a calculator.   A)0.337 B)-2.838 C)0.058 D)-0.231

e9-4x = 7472 We need to express the solution in terms of natural logarithms, having both the EXACT answer and the DECIMAL APPROXIMATION.Somehow got the decimal approximation, but not the exact... more

Let f(x)= -5ln(6x)   I can't figure out how to find the fourth derivative.   f'(x)= -5/x   f'(4)= ___  

Write an exponential decay model for the value of the car.After about how many years will the car be worth half of its purchase price?

ln(x+4) - ln18 = ln5

7 e^x = -2 e^x + 5   Find x where e is the base of a natural log

My teacher will give me extra credit if I can prove that   log(a^x) = 1/log(x^a)   Can you help? Thank you.

LIM x→1+       ((1/LN(x)) - (1/x2-1))

Solve for x and give answers as exact solutions