Answer:
Eleana is 20 years old and her grandfather is 80 years old.
Explanation:
So first off, we want to make variables to represent Eleana and her grandfather.
Let x represent Eleana's age.
Since her grandfather is four times older than Eleana,
The expression should be 4x+x=100
Step One
Add the x's together and you get 5x=100.
Step Two
Divide both numbers by 5 to solve for x.
x=20