y is the amount of money in Susan's account after x weeks.
y is also the amount of money in CiCi's account after x weeks.
You want to know the number of weeks, x, it takes for the amounts in the accounts to be equal. You want Susan't y to equal CiCi's y.
Set the equations equal to each other and solve for x.
65 + 23x = 119 + 14x
Subtract 14x from both sides.
65 + 9x = 119
Subtract 65 from both sides.
9x = 54
Divide both sides by 9.
x = 6
Answer: They will have the same amount of money in 6 weeks.
Check
In 6 weeks, x = 6.
Susan: 65 + 23x = 65 + 23 * 6 = 65 + 138 = 203
CiCi: 119 + 14x = 119 + 14 * 6 = 119 + 84 = 203
In 6 weeks, both Susan and CiCi have $203 in their accounts.