Final answer:
To solve the problem, we set up an equation and solve for the initial amount of money Mia had. After calculation, it is found that Mia had 0.5 units of money at first.
Step-by-step explanation:
To solve this problem, we can set up an equation. Let's assume Mia had x units of money at first.
Since the ratio of Mia's money to Jaci's money was 4:7 at first, Jaci had 7/4 times as much money as Mia.
After Jaci gave 3/14 of her money to Mia, their amounts became equal.
We can set up the equation (7/4)x - (3/14)(7/4)x = x, and solve for x.
Simplifying the equation, we have (7/4)x - (3/14)(7/4)x = x.
Multiplying both sides by 14, we get 49x - 3(7x) = 14x.
Expanding the equation, we have 49x - 21x = 14x.
Combining like terms, we have 28x = 14x.
Dividing both sides by 14, we find that x = 0.5.
Therefore, Mia had 0.5 units of money at first.