SOLUTION: ln(x-7)+ln(x+9)=ln(9) Solve for x What I have done: ln[(x-7)(x+9)]=ln(9) ln(x^2+2x-63)=ln(9) x^2+2x-72=0 Then I get stuck If you could help that would be great!!

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: ln(x-7)+ln(x+9)=ln(9) Solve for x What I have done: ln[(x-7)(x+9)]=ln(9) ln(x^2+2x-63)=ln(9) x^2+2x-72=0 Then I get stuck If you could help that would be great!!       Log On


   

Question 672277: ln(x-7)+ln(x+9)=ln(9) Solve for x
What I have done:
ln[(x-7)(x+9)]=ln(9)
ln(x^2+2x-63)=ln(9)
x^2+2x-72=0
Then I get stuck If you could help that would be great!!
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Perhaps you were assuming that the quadratic is factorable over the integers. It is not. Use the quadratic formula. Hint: 292 factors to 4 times 73.

John

My calculator said it, I believe it, that settles it
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