logarithmic equations

Fizban140

I do not understand this crap at all and my book gives no useful examples. I have 3 log2 (x+1) - 2 = 13
What the heck do I do? I guessed and added 2 to each side and then divded by 5 giving me log 2 (x+1)= 5
From here my book says to do some magic stuff like this 10^5 = x+1 but I do not get the correct answer. What am I suppose to do?

Newton

Just remember that log base a (x) = N means that a^N = x. It looks like you are doing the problem right, but maybe are using the wrong base in your final step. I think the way you wrote the original problem, you are using base 2, not 10.

Fizban140

Oh ya I got it now, it was suppose to be 2^5.

Fizban140

For some reason I was having an incredibly hard time reducing this:

6 +- i2 / 4 it is suppose to go down to 3+-i/2 but I kept getting 3+-i2/2. I got yelled at in class for dividing a problem that was similar to 4 +2 /2 and to reduce it I divided by two but that was wrong in class. What is the rule here? I can divide everything when it is what? I can't divide when it is what?


I also do not understand these x^2 + x + 64 = 0
According to my book I make it =64 then add whatever number I need to factor the left side and then I solve for x. How the hell does that work? I could take away 1000 from each side and have a very different answer than if I added 6 to each side.