Julio's father is 4 times as old as Julio. The sum of their ages is no less than 55.



Enter an inequality that can be used to represent this situation in the first box, where x represents Julio's age.

Enter the youngest age Julio can be in the second box

Respuesta :

Julio is x years old and his father is y years old:
y = 4 x
x + y ≥ 55
x + 4 x ≥ 55
An inequality is:
5 x ≥ 55
x ≥ 55 : 5
x ≥ 11
The youngest age Julio can be is 11.
Call F the age of the father and J the age of Julio.

The F and J are related in this way: F = 4J

Now you have a restriction in the form of inequality: The sum of both ages has to be greater or equal than 55.

Algebraically that is: F + J ≥ 55

You can substitute F with 4J to find the solution for J:

4J + J ≥ 55

5J ≥ 55

Now divide both sides by 5

5J/5 ≥ 55/5

J ≥ 11

That imposes a lower boundary for the value of J of 11, meaning that the youngest age of Julio can be 11.