I need help once more.

[thetomps]

I am still working on this log assignment. This should be the last one I need to confirm.

log9 (5x + 5) = log9 (5x + 4)

Would the correct answer be 5/4?

 

[tkhunny]

I see your screen name on 55 posts. i was hoping you had learned to provide a bit of detail on your solution. It is most helpful to see what work you have done it obtaining your solution.

Your answer is not correct, but you have not provided sufficient information to enable any actual assistance.

Normally, answers for 'x' would be in the form "x = something".

Why is this in the calculus section? If you are in calculus, and struggling with this problem, you're toast.

 

[stapel]

To check the answer to any "solving" exercise, plug your solution into the original problem, and see if it works. In your case, you are proposing "x = 5/4" as the solution. Assuming "log9()" to mean "log-base-nine of ()", we can check:

. . . . .log₉(5x + 5) = log₉(5x + 4)

. . . . .log₉(5[5/4] + 5) ?=? log₉(5[5/4] + 4)

. . . . .log₉(25/4 + 20/4) ?=? log₉(25/4 + 16/4)

. . . . .log₉(45/4) ?=? log₉(41/4)

Applying the change-of-base formula gives us:

. . . . .ln(45/4)/ln(9) ?=? ln(41/4)/ln(9)

. . . . .ln(45/4) ?=? ln(41/4)

. . . . .2.4203681286... ?=? 2.3272777055...

Since the two sides do not evaluate to the same number, it is unlikely that your solution is correct.

Please reply showing all of your steps and reasoning. Thank you.

Eliz.