Question 1198730
amelia is 16 years old
she is 4 times as old as her brother.
that means her brother is 4 years old.
amelia will be twice her age in 16 years.
her brother will then be 20.


that's what i get from the way the problem is stated.


you might have been asking how old amelia was when she is twice the age of her brother.
that's a different euqation.
we start with 16 = 4x, where x is the age of her brother.
that gets us x = 4, as before.
let y = the number of years before she becomes twice the age of her broher.
the equation for that is 16 + y = 2 * (4 + y)
simplify to get 16 + y = 8 + 2y
\subtract 8 from both sides of that equation and subtract y from both sides of that equation to get 16 - 8 = 2y - y\
simplify to get 8 = y
that says that she will be twice as old as her brother in 8 years.
she will be 24 and her brother will be 12.