reinout-g

Sorry Melody, you may want to adjust some things;

$$5x-6 \neq 0$$

$$x \neq \frac{6}{5}$$

and

$$(2x+1)(5x-6) = 10x^2+5x-12x-6$$

which is

$$10x^2-7x-6$$

but since $$-20x^2+14x+6 = -2(10x^2-7x-6)$$

The rest does work.

Nevertheless the hole is at x= 6/5

$$y = \frac{10230158989321}{2500} - \frac{x}{2500}$$

or

$$x = 10230158989321 - 2500y$$

25/75 = 5/15 = 1/3

so 1/3 is the simplest form

I don't know what you mean (no pun intended) by typical number. The mean is the sum of all entries divided by the number of entries. For example, if we have 3,7,2,8,5 then the mean is given by (3+7+2+8+5)/5 = 5. The median is the 'middle' number of the chronically labeled entries. For example if we have 2,6,5,3,8,9,6 then the median can be found by chronically ordering the entries ( 2,3,5,6,6,8,9 ) and picking the middle number (6).

If by typical you mean most commonly used, I believe the mean is more commonly used than the median. This however does not yield that it is a better method! 

BUMP!!! 

BUMP!!! 

Basically 

3.68/3.20 = 1.15 and therefore the price has increased by 0.15*100 = 15%

Try it yourself

at web2.0calc.com

Imagine a square of 40mx60m

Such a square has two sides of 40m and two sides of 60m

Therefore the total length of all the sides would be

40+40+60+60 = 200m

A fence of 200m would therefore be needed.