Profits Math formula

Profits math formulaSecondary school education and math learning point ( losses-profits)

1/  buy a object its meaning valued the object.
2/buy more than sell valued .
3/ profits = buy - profits
4/ loss  =buy - sell
5/buy = (buy - profits) or ( buy +loss).
6/  buy = ( buy + profits) or ( buy - losd)
7/ interest of purchase = profits×100/ buy
8/ loss of purchase = losd × 100/buy
9/ invest = buy + cost
10/ Ned p=br;
There p = Ned profits , b = invest ,r= rate of interest
11/ interest and principal money = interest + principal money.
12/ rate of purchase = interest× 100/Time×principal money
13/ interest = p × r × time/100
14/ principal money = i × r / rate of interest × time
                **Invest and profits formulation**
X% rate of simple interest p rate of money  n for year
1/ I = pnr tk. There  I = simple interest
     P= principal money n = time
2/
S = p+1  = p+pnr=p(1+nr)
                           **Circle interest**
X% rate of circle interest  p tk invested n = year.
Principal money c = p(1+r)n
Circle interest  I = (C-P)
C= circle interest
r = rate of interest.

             Thanks everybody