3 yrs ago father was 4 times the age of his son. if X and Y represent the present age of father and son.Find the relation between X and Y.?plzz give answer

Expert Answers
pohnpei397 eNotes educator| Certified Educator

In this problem, you are simply asked for the relationship between the two variables.  You are not asked to find the actual ages of the two because there is not enough information to find the ages.

Here is what you can say:

The age of the father 3 years ago was x - 3.  The age of the son was y - 3.  We know that the father was 4 times the son's age at that point.  Therefore

x - 3 = 4(y - 3)

So we can say

x - 3 = 4y - 12

x = 4y - 9

You can test this.  Let's say the father was 24 and the son was 6.  Now they are 27 and 9.

27 = 4(9) - 9

27 = 36 - 9

This is true so we have the correct relationship.

neela | Student

As sugested, x be the age of father. and y be the age of son.

There their ages three years ago are: x-3  father's age and y-3 son's age.

It is given that father was 4times the age of son. So x-3 = 4times (y-3). Or

x-3 = 4(y-3) is the relation. Or

x = 4y-12+3 . Or

x = 4y-9  is a relation to get x as a solution if you know y. Or y = (x+9) /4 is arelation to know y throguh x.




giorgiana1976 | Student

Let's establish the followings:

x = the age of the son, now

y = the age of the father, now.

x-3 = the age of the son, after 3 years.

y-3 = the age of the father, after 3 years.

After 3 years, the father's age will be:

y-3 = 4(x-3) 

We'll open the brackets and we'll get:

y-3 = 4x-12