Melody

\((3x+3)(x-4)=3(x+1)\\ 3x^2-12x+3x-12=3x+3\\ 3x^2-9x-12=3x+3\\ 3x^2-9x-12-3x-3=3x+3-3x-3\\ 3x^2-12x-15=0\\ \text{divide both sides by 3}\\ x^2-4x-5=0\\ (x-5)(x+1)=0\)

now if 2 things multiply together to give 0 then one of them, or both of them, must equal 0.

so

x-5=0      or      x+1=0

x=5         or         x=-1

I do not understand what the question is saying..... 

The bouy is at the surface isn't it? Why do we care about the ocean depth?   I don't get it.

measures of central tendency are   mean, mode and median.

Start by putting all thes scores from smallest to biggest.  

the mean is just the average, add them all up and then divide by how many there are.

The median is the one or average of the two that are in the middle

the mode is the score that haapens the most.  (there can be any number of modes)

measures of dispersion?

range, interquatile range, standard deviation.   Ar they the ones that you want?  Do you know how to find them?

I always forget about L'hopital's rule - thanks for you answer and thanks for reminding me.

Bur....

Why not just use l'hopital's rule to start with?

\(\displaystyle\lim_{x\rightarrow 1}\;\;\frac{xlnx}{1-x}\\ =\displaystyle\lim_{x\rightarrow 1}\;\;\frac{lnx+1}{-1}\\ =-1\)

Reposted here:

This is a repost of this question:

It only has the calc on the home page.

I told you before.

Just graph them in here and see for yourself!

Have you tried googling it?