Final answer:
To find Eric's grandfather's age, algebraic equations are set up using the given relationships. Eric's grandfather is found to be currently 73 years old by solving these equations.
Step-by-step explanation:
To solve the problem of determining Eric's grandfather age, we need to establish a relationship between Eric's current age and that of his grandfather, using algebraic expressions. Let's assume Eric's age is E and his grandfather's age is G. From the question, we know the following:
- Eric's grandfather is 57 years older than Eric: G = E + 57.
- In three years, Eric's age will be E + 3, and his grandfather's age will be G + 3.
- At that point, Eric's grandfather will be four times Eric's age: G + 3 = 4(E + 3).
Now we can set up the equations to solve for E and G:
- G = E + 57
- G + 3 = 4(E + 3)
Substitute G from the first equation into the second equation:
- E + 57 + 3 = 4(E + 3)
- E + 60 = 4E + 12
- 60 - 12 = 4E - E
- 48 = 3E
- E = 16
Now we can find Eric's grandfather's age:
Therefore, Eric's grandfather is currently 73 years old.