Tuesday

July 22, 2014

July 22, 2014

Posted by **Laura Grace** on Wednesday, March 23, 2011 at 9:55pm.

ln(X+5) = ln(X-1) - ln(X+1)

The answer has no solution but I do not know how to come to that answer. Help is greatly appreciated!

- pre calc -
**Reiny**, Wednesday, March 23, 2011 at 10:06pmln(x+5) = ln[(x-1)/(x+1)]

x+5 = (x-1)/(x+1)

(x+5)(x+1) = x-1

x^2 + 6x + 5 = x-1

x^2 + 5x + 6 = 0

(x+2)(x+3) = 0

x = -2 or x=-3

but in ln(x-1), x-1>0 or x > 1

remember we can't take the log of a negative number and we would get ln(-3) and ln(-4) which would be undefined.

so neither of the solutions are valid, and

there is no solution to your equation.

- pre calc -
**Laura Grace**, Thursday, March 24, 2011 at 8:44pmThank you soo much!

**Related Questions**

PRE CALC - Use matrices to solve the system. (If the system has infinitely many ...

Pre-calc - The question is solve for cosx= 0.60 on the interval [0,2pi). The ...

pre-calculus - solve the equation 1. In x + In (x+12) =2 x= ? or either there is...

Pre-Calc - Evaluate the indicated function for f(x)=x^2-8 and g(x)=x-4 (fg)(3) ...

Pre-Calc - I'm stuck on a pre-calc problem. I need to find y as a function of x...

8th Grade Algebra- Answer Check - Solve each system of equations, give the ...

precalc - I'm terrible at pre calc, could someone tell me if the solution set ...

Algebra 2/Math - Can you check these thanks. Solve the system by substitution or...

pre-ap pre calculus - To solve an equation by finding x-intercepts, Cynthia ...

Derivatives - Find the derivatives of: 1. H(x)= sin2xcos2x The answer given is ...