Answer:
x = 4
Step-by-step explanation:
Extracting the key information from the question:
*** A fraction has 20 as its denominator.
*** The value of the denominator = 20 - x
*** If the fraction is equivalent to or the same as 4/5.
*** We are basically required to calculate the value of x.
Since we are not told what the fraction is equivalent to, we can fix any random fraction in order to help us to understand what we are basically required to do in to get through this sort of question. Now, let us assume that the fraction that this unknown fraction is equivalent to is 4/5.
We have also been informed that this fraction has a denominator of 20 and a numerator that is x less than the denominator. This means/ signifies that the denominator = 20 and the numerator = 20 - x.
i.e the fraction in question = (20 - x)/20.
Since this very fraction is equivalent to 4/5, then:
20-x/20 = 4/5
We will then cross multiply and make "x" the subject of the formula.
(20-x)×5 = 20×4
100 - 5x = 80
5x = 100 - 80
5x = 20
x = 20/5
x = 4
