How to get a number dependent on another pure?

Question

Mathematics

There is a number that can take values ​​from 6 to 0 (maybe from 10 and from 40 but not less than 0).
The question is:
How to get interest from this number, let's say, or I don’t even know what it is.
If the number = 7 then the second number is 0 if the number = 0 then the second number is 1 and in the interval it should turn out not an integer there (the option with 6 and 0) the number = 3 then it should turn out 0.5
Help

Answer 1

If my crystal ball is not broken, then we are talking about a linear function, the graph of which is a straight line. And two points through which this line passes are known:
Suppose two points D1 with coordinates (x ₁ , y ₁ ) and D2 with coordinates (x ₂ , y ₂ ) are given. Then the equation of a straight line through them can be written as follows:
( x - x ₁ ) / (x ₂ - x ₁ ) = ( y - y ₁ ) / (y ₂ - y ₁ )
In this case, this is

(x – 0)/(6 – 0) = (y – 1)/(0 – 1)
x / 6 = (y – 1) / –1
–x / 6 = y – 1
y = 1 – x/6

If, for example, x=4, y = 1/3
More about the equation of a straight line through two given points on the plane. I drew the graph in the free GeoGebra program (including in Russian) - I highly recommend it for explaining / understanding mathematics and geometry.

Answer 2

Klitschko, are you