Friday

March 27, 2015

March 27, 2015

Posted by **Claudia** on Friday, July 26, 2013 at 10:26pm.

2.solve 4(3^2x)=e^x

- math -
**Reiny**, Friday, July 26, 2013 at 10:56pm1. take ln of both sides

ln(x e^x)^2 = ln(30 e^-x)

2 lnx + 2ln e^x = ln30 + ln e^-x

2lnx + 2x = ln30 -x

2 lnx = -3x + ln30

lnx = (-3/2)x + (1/2)ln30 or (-3/2)x + ln (√30)

comparing this with ax + b

a = -3/2 , b = ln √30

2. take ln of both sides and use rules of logs

ln (4(3^2x) ) = ln e^x

ln4 + xln3 = x

x - 2xln3 = ln4

x(1 - 2ln3) = ln4

x = ln4/(1-2ln3) or appr. -1.1579

check:

LS = 4(3^-2.3158... = .31413784

RS = e^-1.157923.. = .31413784 , how about that?

**Answer this Question**

**Related Questions**

math - how would you solve for y in this problem: ln(y-1)-ln2 = x +lnx ln(y-1)-...

calculus - (a) find the intervals on which f is incrs or decrs. (b) find the ...

L'Hopital's rule - Find lim x->1+ of [(1/(x-1))-(1/lnx)]. Here is my work...

Calculus 1 - Find the derivative of y with respect to x. y=(x^6/6)(lnx)-(x^6/36...

math - I am suppose to simplify the following problems: sqrt(x)/x (isn't that ...

statistics - Does anyone know how to solve these two problems. Solve the problem...

Math logs - Solve the system of equations: y= (lnx)^2 + 2 (lnx^2) y = 3ln(1/x^2...

Math (Calculus) - Can somebody solve this logarithm problem step by step for me ...

Math - I cant figure this question out. I could use some help. Solve for x lnx-...

algebra 2 - Would some one look at these problems and see if I got them right ...