Melody

I think that exp usually means 10 to the power of - but it still doesn't make sense.

Another big one lost.

This is really painful.

We need a draft availability.

Anyway, this is what I used

The dimensions of a 2 liter bottle depends on the shape. A 2 liter soda bottle is 12.25 inches high and 4 inches in diameter. 

from

w+w+(w+8)+(w+8)=52

4w+16=52

you can probably solve this.  

then you know that l=w+8   

$$\\4logx^{3}-3logx^{2}=12\\
log(x^3)^4-log(x^{2})^3=12\\
log(x^{12})-log(x^6)=12\\
log(\frac{x^{12}}{x^6})=12\\
log\;x^{6}=12\\
6log\;x=12\\
log\;x=2\\
10^{log\;x}=10^2\\
x=100$$

Log(36,10) + 2log(5,10) - log(9,10)

$$\\log36+2log5-log9\\
=log36+log25-log9\\
=log(36*25/9)\\
=log(100)\\
=2$$

$$\begin{array}{rlll}
-2i(2+5i)&=&x+6i\\
-4i-10i^2&=&x+6i\\
-4i+10&=&x+6i\\
-10i+10&=&x\\
x&=&10-10i\\
\end{array}$$

The ones that graph to a line with a positive gradient are directly proportional to.  

Well they are both over 2 in that this is true

$$\frac{125}{2}+\frac{81}{2}=\frac{125+81}{2}$$

but you wouldn't do it like that

You would just add up the top and THEN divide by the bottom.  It's much quicker.  

I was trying to finds a good page for you but I couldn't find one that I was completely happy with

basically if two things have direct variation then as one gets bigger so does the other - and vise versa

the example in the first web page is distance traveled and time taken.

time taken is directly proportional to distance travelled because 

the longer the travel time the futher you travel.

Have a look at these web pages if you want more into.    

I just found a whole heap more on pages 663 and 664 .