why in math, whenever you do an explanation, for example, 2x - 20, the subtraction sign make the 20 a negative number?

The negative sign is put before numbers to make them negative, or make their signs the opposite of what the are.

You have a 20.

+ 20

You don't need to put the + there if there is nothing before it, but that is a positive 20.

If you put a negative in front of it;

- (+ 20) = - 20

If you have a negative in front of parenthesis;

50 - (2x - 20)

50 - 2x + 20

70 - 2x

his chances of getting a coin of higher value is 4/19

step-by-step explanation:

need more info

step-by-step explanation:

what do you mean by "representation"? graph? table? etc.