20002 because all of it added together and then divided by two gives you 20002.
Call (F) the age of the father and (J) the age of Julio
The F & 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
I think none of these are right. It's Y=-5/3x +4/3
y = −2x + 1
4x + 2y = −1
Replace Y in the second equation with the value of Y in the first one.
4x + 2(-2x +1) = -1
Distributive Property:
4x + -4x + 2 = -1
Combine like terms:
2 = -1 which is not true, so there are no solutions.
The answer for this problem is D